Site-specific genome editing refers to the genetic manipulation techniques that can precisely modify DNA sequences at the genomic level, which holds a great application value in analysis of gene function, plant genetic improvement or development of new varieties. The general working principle of genome editing is that the sequence-specific nucleases (SSNs) are used to create DNA double-strand breaks (DSBs) at the genomic target sites that will be repaired through non-homologous end joining (NHEJ) and/or homology-directed repair (HDR) pathways, resulting in nucleotide insertion, deletion, or DNA fragment replacement in the targeted gene(s). Nowadays, genome editing technologies including Zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and clustered regularly interspaced short palindromic repeats/CRISPR-associated proteins (CRISPR/ Cas）system have been successfully applied in genetic improvement of crops. From the perspective of development trend, CRISPR/ Cas system-based genome editing technology will become the core technology in genetic improvement and molecular design breeding of crops. This review starts with brief introduction of the concepts and working principles of ZFNs, TALENs and CRISPR/Cas system, and focus on the recent progress of genome editing-based crop improvement of yield, quality, disease resistance, abiotic stress resistance and rice male sterile line development. Then the authors sorted out the technological innovation and application of CRISPR/Cas-based single-base editing for plant genomes and the DNA-free plant genome editing system in details. After comparing the advantages and disadvantages of different genome editing techniques, some general principles of adoption of genome editing technologies in crop improvement were put forward. Finally, the regulations on genome-edited crops, as well as the opportunities and challenges of genome editing-based crop breeding were discussed.

【Objective】The awn has a significant influence on stress resistance and spikes photosynthetic characteristics in wheat. The objective of this study is to explore the principal-effect QTLs which control the stable expression of awn and their close chain or total separation of molecular markers, and to provide evidences for molecular marker assisted breeding, constructing near-isogenic line, screening candidate gene and cloning novel genes.【Method】Two F₉ RIL (recombinant inbred lines) populations derived from XY81/Z8425B and XY81/XN1376 were used as drawing population, and two linkage maps were constructed by using 90K array which covering 21 chromosomes of wheat, and the two F_9﹕10 families which including 102 and 120 lines, respectively, were used for the identification of field traits. The two F9:10 families were planted in Yangling District (Shaanxi Province), Nanyang City (Henan Province) and Zhumadian City (Henan Province) from October 2016 to June 2017, respectively. The phenotypic data of awn length of two populations were used to detect QTLs by using the complete interval mapping and multi-environment joint analysis at the ripening stage.【Result】Two genetic maps covering 21 chromosomes of wheat were constructed, the total length of map was 4 412.14 and 4 281.67 cM, respectively. And the average genetic distance was 2.65 and 2.31 cM, respectively. The number of linkage markers in the two linkage maps indicated that the 90K marker was unevenly distributed in wheat genomes A, B and D, but was all expressed as the number of markers in genome B＞that in genome A＞that in genome D. The common marker of D genome was the least for the common markers of two linkage maps, and it indirectly reflected that the D genome was highly conserved. Six QTLs were found in two RIL populations from Yangling District (Shaanxi Province), Nanyang City (Henan Province) and Zhumadian City (Henan Province). The major QTL, Qal5A-1, showed a strong stability in two populations under three environments and was belonged to environment-insensitive QTL. The phenotypic variance explained by Qal5A-1 ranged from 46.01% to 79.82%. It showed inhibitory effects on awn length, and the additive effects came from parent Xiaoyan 81. This major QTL was mapped at the end of chromosome 5A and was closely linked to the molecular marker RAC875_c8121_1147. The phenotypic variance explained by 5 QTLs, including Qal6B-1, Qal1B-1, Qal3B-1, Qal2D-1 and Qal2D-2, were 1.39%, 3.66%, 3.93%, 5.53% and 3.51%, respectively, which were micro-effect QTLs. Two QTLs were found in the RIL group derived from XY81/Z8425B, including one major OTL Qal5A-1 and one micro-effect QTL Qal6B-1, the two loci explained the phenotypic variance was 79.91%. Five QTLs were found in the RIL group derived from XY81/XN1376, including one major OTL Qal5A-1 and four micro-effect QTLs Qal1B-1, Qal3B-1, Qal2D-1 and Qal2D-2, the five loci explained the phenotypic variance was 63.96%. Six QTLs were obtained by multi-environment analysis, and the contribution rate of phenotypic variation of their interaction effects was much lower than that of additive effect, which indicated that the interaction between QTL and environment was not the main factor of influencing awn length. The additive effect values were approximately equal in different environments, further indicating that these six QTLs had a stable genetic effect among the three environments. 【Conclusion】The dominant QTL, Qal5A-1, was detected in two groups. It can be stably expressed and closely linked to the molecular marker RAC875_c8121_1147. It explains the phenotypic variance from 46.01% to 79.82%, which has a strong inhibitory effect on awn length.

Cotton is the longest chain of field commercial crops of China’s planting industry, which the commodity rate is as high as more than 95%, but still exists many shortcomings of the cotton industry which require further attention from cotton enterprises, cotton farmers, scientific and technical personnel, and scholars, such as independent seed industry, brand cultivation, cleaner production, unified management and pest control, dependence on foreign trade, industrial security and economies of scale, industrial organization and other factors that influence China's cotton industry competitiveness and sustainable development. The major production areas of cotton in China are Xinjiang, the Yellow River basin and the Yangtze river basin, for example, Xinjiang cotton production accounts for 67% of the national output and has formed scale and mechanization planting, but the Yangtze river basin and the Yellow River basin still practice the small scale economy, not full play the leading role of the new type of management main body, the scale planting and mechanized production, is lack of the integrated data platform of cotton production can not be formed, and processing and marketing, and only several departments are engaged in professional service, one-on-one full service and hosted service. The development direction and goal of cotton production in China should be improved the level of cotton production scale, mechanization, intelligence, informationization, socialization service, development of light-simplified production technology that makes cotton farmers to grow cotton more happily and with more dignity, reduce production cost, solve the problem who is going to a tiller of the ground, control tightly cotton industry chain. From the Angle of the cotton industry chain of supply and demand, this paper expounded the present situation of development of cotton industry that the Chinese cotton planting area and output decreased, the industrial layout in Xinjiang outshines others, the domestic consumption has decreased, but the supply and demand situation has been improved, the imports are greater than the exports over a long period of time and the advantages of textile industry decreased gradually, and so on. A series of problems about Chinese cotton industry in the production process, the industrial layout, organization and management, and platform construction were analyzed. Based on the practice of the growing experience and development advantages of the United States and Australia in cotton varieties, production technology, mechanization and national policy, combining with the policy background of China's reform of structure of the supply side, the corresponding countermeasures and suggestions were put forward including cultivating new cotton varieties, researching new technology of light-simplified and mechanized production, the input of agricultural machinery equipment, optimization of varieties, quality and area layout, scientifically preventing and controlling plant diseases and insect pests to improve the quality of cotton, develop cotton price target system, improve the insurance amount of cotton production, increase subsidies and policy support dynamics of cotton farmers, cotton business, agricultural machinery manufacturers, textile companies, exporters and so on, giving play to the advantages of production and cotton association function, building platforms of production-supply-sales integration, perfecting the regulation system of cotton supply and demand, construction of the modern cotton industry service system, driving the cotton and textile industry abroad with the help of One Belt And One Road, and so on, in order to stimulate domestic effective supply, achieve the equilibrium of supply and demand of China's cotton industry as soon as possible. Finally, the prospects for China's cotton industry were presented, the three cuts-one reduction-one subsidy (cut overcapacity, cut stores, cut levers-one-reduction-one subsidy) should be used in cotton industry and conform to the pattern of global cotton to get rid of the inventory, and cotton prices will be higher in the coming two years.

【Objective】This study was conducted to determine the characteristics of high-yield double rice cultivars by using high-yield rice cultivars with suitable growth period in triple cropping pattern of early rice-late rice-interplanting early-maturing rapeseed (rice-rice-rapeseed cropping system), which would provide grounds and references for breeding and cultivation of high-yield double rice cultivars.【Method】9 early rice cultivars and 10 late rice cultivars were employed in field experiments of rice-rice-rapeseed cropping system, and characteristics of high-yield double rice cultivars were studied by using cluster analysis and variance analysis methods.【Result】(1) There were no significant differences in panicle number, seed setting rate, 1000-grain weight and growth period among the three yield types (high-yield (HY), middle-yield (MY) and low yield double rice cultivars (LY) ). However, the number of grains per spike, total spikelet volume, yield and daily yield of HY were significantly higher than that of LY. (2) There were no significant differences in increase rate of tillering, decrease rate of tillering and number of peak tiller between HY and LY, while the rate of effective ear of HY was significantly higher than that of LY. (3) For early rice, HY showed higher biomass in heading and biomass per stem in heading and maturity, followed by MY and LY, with no significant differences among them, yet the total biomass and biomass per stem of HY were significantly higher than that of LY. As for late rice, there were significant differences in total biomass and biomass per stem in heading and maturity between HY and LY. As to harvest index, there were no significant differences among the three yield types of both early and late rice. (4) HY showed higher leaf area index (LAI) and leaf area per stem in heading and maturity, as well as lower reduction rate of leaf area form heading to maturity, followed by MY and LY, with significant differences between HY and LY. And also, HY showed higher spikelet number per leaf area, followed by MY and LY, with significant differences between HY and LY of early rice.【Conclusion】In rice-rice-rapeseed cropping system, high-yield double rice cultivars were characterized by medium tillering ability, high earing rate, powerful abilities of dry matter per stem and high LAI as well as high leaf area per stem in mid and latter stages, large number of spikelets and high daily production. While some differences were existed between early rice and late rice. For early rice, it was about 105-110 d of growth duration, 75-78 kg·hm^-2·d^-1 of daily yield, 125-140 spikelets per panicle, and 26-28 g for 1000-grains. As for late rice, it was about 115 d of growth duration, 77-81 kg·hm^-2·d^-1 of daily yield, large number of the grains (140-160 spikelets per panicle), and 24-28 g for 1000-grains.

【Objective】To study the temperature condition of early rice from transplanting to Maturity in southern China during 1961-2015, combined with different transplant periods of early rice, characteristics of temporal and spatial distribution of temperature suitability and high temperature days from heading - flowering to milk ripe and Maturity of early rice were quantitatively analyzed under the climate change and different transplant periods.【Method】Four planting regions of early rice were divided into Hainan (region 1), South China (region 2), the north of Guangxi (region 3) and the south of the Yangtze River (region 4). The temperature suitability and high temperature days from heading to Maturity were calculated in three scenes of normal and 5 d and 10 d in advance transplant in 4 regions during 1961-2015. Every five days was used to be the study scale. The evaluation index of temperature suitability in critical growth stage of early rice was established based on pentad scale to analyze the responses of heading to flowering and milk ripe and Maturity of early rice to climate change and different transplant period. 【Result】The results showed that: (1) The annual temperature from transplant to Maturity in different regions of early rice was slowly rising and the tendency rate was between 0.097 ℃·(10a)^-1 to 0.192 ℃·(10a)^-1. The 1990s was the fewest days of high temperatures from heading to Maturity, while the most in 21st century. (2) The highest temperature suitability was in region 3 in different ages in the space, while the lowest in region 4. The high temperature suitability distribution in the 1990s was greater than other ages. (3) It was beneficial to improve the temperature suitability in advance transplant in region 1, 2 and 4, but it was opposite in region 3. The high temperature days were reduced in advance transplant in region 2, 3 and 4, but it was opposite in region 1. (4) The characteristic of the temperature suitability in typical station of Meixian in Guangdong province was “down-up-down”, while it was declined significantly after entering 2000. The characteristics of high temperature days were continue to rise, which were 9.6 days in 1960s and 17.2 days during 2011-2015. Meanwhile 5 d or 10 d in advance transplant could raise the temperature suitability and reduce high temperature days. 【Conclusion】In general, it was beneficial to improve temperature suitability from heading to flowering and milk ripe and Maturity of early rice and reduce high temperature days in South China and South of the Yangtze River, which could reduce the influence of high temperature on early rice.

【Objective】Plastic mulching after seeding followed by artificial freeing of seedlings from mulching at full emergence (seeding before mulching, SBM) is widely adopted in the Yellow River valley, but it is labor-intensive and costly. Plastic mulching in advance and seeding on plastic film (seeding after mulching, SAM) can remove the process of seedling freeing and has been widely applied in the drought northwest inland, but it is still unclear if it can be applied in the Yellow River valley and whether the cotton emergence rate and stand establishment will be reduced in case of rain. The objective of this study is to determine the effects of rainfall at emergence on stand establishment and yield of cotton in relation to different seeding patterns, most importantly, is to determine an easy and light planting pattern with good stand establishment and less labor consumption. 【Method】A two-year field experiment was conducted to evaluate the effects of rainfall and seeding patterns on stand establishment, leaf area index, yield and yield components. A split-plot design with three replicates was used for the study. The main plots comprised two simulated rainfalls (0 mm and 10 mm), while seeding patterns including seeding without mulching (SWM), SBM, SAM and seeding under double mulching (SDM) constituted the subplots.【Result】Significant interaction was detected between rainfall and seeding pattern on emergence rate, dry matter accumulation, leaf area index, boll density and cotton yield. Without rainfall, emergence rate, dry matter, leaf area index, boll density and yield of SAM and SDM were similar to those of SBM, but those of SWM were reduced by 13.6%, 19.0%, 13.3%, 24.7% and 27.7% relative to SBM, respectively; Under 10 mm rainfall, these parameters were decreased by 32.2%, 43.1%, 26.3%, 25.8% and 29.2% for SAM, respectively, 42.8%, 55.8%, 47.2%, 35.0% and 40.1% for SWM, respectively, relative to SBM, but all the parameters of SDM were similar to those of SBM.【Conclusion】SAM reduced stand establishment and cotton yield relative to SBM under 10 mm rainfall, but SDW exhibited comparable stand establishment and yield to SBM regardless of rainfall. Therefore, choosing a suitable seeding pattern is an important way to guarantee full stand establishment and high yield in terms of local ecological conditions, especially the rainfall probability.

【Objective】The aim of this study was to reveal the relationship between the cadmium contents of tumorous stem at mature period and leaf spectral reflectance at the early stages of tumorous stem mustard (Brassica juncea var. tunida), a famous local vegetable in the Three Gorges Reservoir Region. The results could provide theoretical guidance for predicting cadmium contents of tumorous stem of tumorous stem mustard rapidly and accurately, which was helpful to know the edible quality in the early growth stage of vegetable. 【Method】A pot experiment was conducted to set up 0, 0.1, 0.2, 0.3 and 1 mg·kg^-1 with different concentrations of cadmium in soil (calculated according to dry soil weight) based on the present situation of soil cadmium contamination in the main planting area of tumorous stem mustard. The leaf spectral reflectance and cadmium contents were synchronously determined in the main four growth periods of vegetable. Wavelet-Fractal Analysis was used to obtain detailed information about leaf spectral reflectance based on db2-db8 wavelet bases under the fifth dimension. Using correlation and regression analysis, non-linear models were constructed for estimating cadmium contents of tumorous stem of tumorous stem mustard advanced in the early growth stage. 【Result】There was a relatively intense accumulation of cadmium in the leaves and tumorous stem of tumorous stem mustard, which increased with the increased cadmium concentrations in soil. There was a significant positive correlation between the cadmium contents of the tumorous stem and the leaves. The leaf spectral reflectance in four growth stages, especially in the early enlargement stage of tumorous stem, could well respond to the contaminated cadmium in soil. The fractal dimension coefficients of leaf spectral reflectance based on "db2-db8" were significantly negatively correlated with the leaf cadmium contents in the early enlargement stage of tumorous stem. The models were simulated based on the relationships among the cadmium concentration in the tumorous stem at mature period of tumorous stem mustard, the leaf fractal dimension coefficients in the early enlargement stage of tumorous stem and the contaminated cadmium in the soil. The model based on "db5"was the optimal simulation, which R² was 0.929 and Root Mean Square Error (RMSE) was 1.0540. 【Conclusion】The results showed that cadmium could accumulated in leaf and tumorous stem of tumorous stem mustard, which could threaten the human health and the food safety, so it should be paid more attentions. Wavelet-Fractal Analysis was suitable to assess the situation of heavy metal contamination of vegetable due to its sensitivity for subtle spectral information. The optimal model was established based on wavelet db5 of leaf spectral reflectance, that was Y=-0.029+32.878X^-7.656, with R² and RMSE was 0.929 and 1.0540, respectively, which could accurately predict the cadmium content of tumorous stem at the mature stage by using the spectral data from the early growth stage, and provide a theoretical foundation for knowing the edible quality in the early growth stage of tumorous stem mustard.

【Objective】The objective of this study is to clarify the toxigenic chemotype and genetic diversity of Fusarium graminearum species complex (FGSC) causing maize ear rot from different provinces (autonomous region).【Method】The toxigenic chemotypes of 92 FGSC isolates collected from 11 provinces (autonomous region) were analyzed by using the specific primer designed based on Tri13 and Tri3 sequences. Thirteen primers with abundant bands, good repeatability, strong signal and clear background were screened from 100 universal primers developed by Columbia University (UBC) and used for ISSR-PCR amplification of these isolates. The Popgen32 software was used to calculate the percentage of polymorphic loci, Shannon’s diversity index, genetic distance and genetic similarity among populations. According to Nei’s genetic distance, UPGMA cluster analysis was carried out using NTsys2.10e software, and the dendrogram of different geographical populations was constructed. 【Result】 Four different toxigenic chemotypes including DON, 15-ADON, DON+15-ADON and NIV+15-ADON were detected among 92 FGSC isolates. One and 20 isolates represented the DON and 15-ADON chemotypes, respectively. One isolate produced both 15-ADON and NIV, and 55 isolates carried both 15-ADON and DON producing segments. The PCR amplification of all FGSC isolates was performed with 13 ISSR primers and a total of 102 fragments were obtained, of which 101 fragments displayed polymorphic and accounted for 99.02% in the total amplified fragments. The average number of fragments amplified per primer was 7.85. At population average level, the Nei’s gene diversity index (H) was 0.3129 and the Shannon’s information index (I) was 0.4774, which indicated that there was a high genetic diversity in FGSC isolates. The diversity existed among fungal populations from different geographic regions. Hebei, Shanxi, Heilongjiang and Jilin had the highest genetic diversity, while Anhui and Henan had the lowest genetic diversity. The genetic differentiation coefficient (Gst) of geographical populations was 0.2722, indicating that there were some genetic variations among different geographical populations, but most of the genetic variation (72.78%) occurred in the population. The Nm=1.3372 (＞1) indicated that there was a certain gene flow among different geographical populations. The results of genetic relationship showed that the populations of Hebei, Shanxi, Heilongjiang, Jilin, Liaoning, Inner Mongolia and Gansu were relatively close, and the populations of Shandong, Jiangsu, Henan and Anhui also displayed a close relationship, whereas the population isolated from Anhui had the lowest similarity with population isolated from Inner Mongolia. Cluster analysis showed that the similarity coefficient of all isolates was 0.43-0.95. All the isolates were divided into two groups with the similarity coefficient of 0.43. Group 1 included 4 isolates of northern spring sowing region (Jilin, Shanxi and Zhangjiakou, Hebei), which did not produce NIV and DON. Group 2 consisted of the remaining 88 isolates which originated from northern spring sowing region (Shanxi, Heilongjiang, Jilin, Liaoning, Gansu and Hebei (Zhangjiakou and Tangshan)) and Huang-Huai-Hai summer sowing region (Henan, Shandong, Jiangsu, Anhui and Shijiazhuang, Hebei), and the toxins produced by these isolates were mainly DON and 15-ADON. When the similarity coefficient was 0.664, each group was divided into different subgroups, and the results of subgroups were related to the source of the isolates.【Conclusion】The main toxigenic chemotypes of FGSC from northern spring sowing region and Huang-Huai-Hai summer sowing region are DON and 15-ADON. There are abundant genetic variations in the populations of FGSC causing maize ear rot. There are certain gene exchanges among different geographical populations. The genetic diversity was related to the geographical origin.

【Objective】 Fungal polysaccharides can regulate plant growth, activate plant defense responses, and induce plant resistance to plant fungal and viral diseases. The objective of this study is to investigate the induction effect of sharp eyespot of wheat and the effect on wheat growth after Ganoderma lucidum polysaccharides (GLP) seed dressing.【Method】Three wheat cultivars including highly susceptible cultivar Jimai 22, middle susceptible cultivar Shannong 23 and resistant cultivar Luyuan 502 were chosen to test. Using the pot culture method, each pot was added with 20 mL of pathogenic fungi suspension, seeds were treated with the GLP, the control group was treated with water. The disease index and disease reduction against sharp eyespot of wheat were investigated. The mechanism of induced resistance in terms of defense enzyme activity, chlorophyll and malondialdehyde (MDA) content were evaluated. At the same time, the germination rate, plant height and root vigor were determined. 【Result】After GLP seed dressing, Jimai 22, Shannong 23, Luyuan 502 cultivars had the same rule on sharp eyespot of wheat. GLP seed dressing promoted the growth of wheat, 4, 8 g a.i./100 kg seed dose of GLP of Jimai 22 seed germinating potential were 53.50% and 52.75%, significantly higher than that of the control. After 7 d of wheat emergence, the plant height of wheat treated with GLP was significantly higher than that of the control group, and the higher the treatment dose, the more obvious the effect of induction enhancement. GLP seed dressing could significantly improve the root activity and the chlorophyll content of wheat, the root activity of 8 g a.i./100 kg seed dose of GLP of Jimai 22 was 0.26 mg·g^-1·h^-1, which was 2.77 times than that of the control. The chlorophyll a and b contents of 8 g a.i./100 kg seed dose of GLP were 1.96, 0.96 mg·g^-1, respectively, which was 1.52, 1.44 times than that of the control. GLP seed dressing could produce certain effect on prevention and control of sharp eyespot of wheat. Take the highly susceptible cultivar Jimai 22 as an example, 8 g a.i./100 kg seed dose of GLP in wheat seed dressing, the control effects on sharp eyespot of wheat were 33.7%, 31.9% and 30.4% on the 7, 14 and 21 d after wheat completely germination. At the same time, the protective enzyme activity of PAL, POD, SOD of leaves increased obviously, while the content of MDA decreased. Eight g a.i./100 kg seed dose of GLP by seed dressing in Jimai 22, the activity of PAL, SOD and POD was 60.72 U·min^-1·g^-1 FW, 2.45 U·g^-1 FW and 135.67 U·min^-1·g^-1 FW, respectively, which was 1.10, 1.32 and 1.13 times than that of the control. The content of MDA was 1.48 μmol·g^-1, which was 26.1% lower than that of the control group.【Conclusion】The wheat seed dressed with GLP can promote the germination of wheat seeds and the growth of wheat seedlings, increase the content of chlorophyll. At the same time, it can also induce wheat sheath blight disease resistance, increase the activity of defense enzymes and decrease the content of MDA in wheat leaves.

【Objective】 If herbicide-resistant transgenes escape from transgenic oilseed rape (Brassica napus, AACC, 2n=38) to their weedy relatives through pollen flow, weeds with the herbicide-resistant trait might produce new problems for weed control. Wild B. juncea (AABB, 2n=36), relative weed of transgenic B. napus, has become a major weed of crop systems across western China, and extended eastward along the Yangtze River valley. In order to provide experimental data for whether the transgene could successfully escape to wild B. juncea, it is necessary to evaluate the fitness of backcross generation between herbicide-resistant transgenic B. napus and wild B. juncea before it is released. 【Method】Wild B. juncea and herbicide-resistant BC₃mF₄R, BC₃pF₄R and BC₃mF₄L, BC₃pF4L (R and L denote glyphosate- and glufosinate-resistant backcross progeny obtained with glyphosate- and glufosinate-resistant transgenic B. napus, respectively. m and p denote backcross progeny obtained with wild B. juncea as maternal plants and paternal plants, respectively) were planted at low (15 plants per plot) and high density (30 plants per plot) in pure and mixed stands (wild B. juncea﹕backcross generation were 4﹕1, 3﹕2 and 1﹕1). the vegetative components (plant height, stem diameter, the first branch number/plant, above-ground dry biomass/plant) and reproductive components (silique number/plant, total seed weight/plant, silique length, seed number/silique) of these backcross generations were measured. The differences of the composite fitness between BC₃F₄ and wild B. juncea were analyzed. 【Result】 Under pure stands, there was no significant difference in the fitness components and composite fitness of BC₃F₄R with that of wild B. juncea. The composite fitness of BC₃F₄L was also similar to wild B. juncea although the stem diameter, above-ground dry biomass/plant, and silique number/plant of BC₃F₄L at high density were significantly lower than that of wild B. juncea. Therefore, either glyphosate- or glufosinate-resistant BC₃F₄ was as fit as wild B. juncea regardless of density under pure stands. Under mixed stands, at low density, there was no significant difference in composite fitness of glyphosate- or glufosinate-resistant BC₃F₄ with that of wild B. juncea. At high density, there was no significant difference in fitness components and composite fitness of BC₃F₄R with that of wild B. juncea regardless planting proportions. However, the plant height, stem diameter, the first branch number/plant, above-ground dry biomass/plant, silique number/plant, total seed weight/plant and composite fitness of BC₃F₄L were significantly lower than that of wild B. juncea. The correlation analysis showed that the fitness components of BC₃F₄ were only related to the planting density. 【Conclusion】Glyphosate- or glufosinate- resistant BC₃F₄ between glyphosate- or glufosinate-resistant transgenic B. napus and wild B. juncea have a strong survival ability and potential possibility of establishing populations in the field. Moreover, the ecological risk of gene flow is higher from glyphosate-resistant transgenic B. napus than glufosinate-resistant transgenic B. napus. Therefore, preventing gene escape from herbicide-resistant B. napus to wild B. juncea should not only prevent their initial hybrids, but also should prevent the backcross between wild B. juncea and F₁ or subsequent generations, so as not to produce higher fitness backcross generation.

【Objective】Application of organic manure can promote soil microorganisms growth and improve soil fertility. However, very rare studies were conducted to quantify the effects of manure application on soil microbial biomass carbon (SMBC) and nitrogen (SMBN) in croplands at national scale. Therefore, quantifying the effects of manure application on the contents of SMBC and SMBN under different climate regions and soil conditions is important to provide theoretical basis for reasonably applying manure, so as to enhancing of soil fertility and microbial activities for China’s croplands. 【Method】In current study, all of 70 literatures, including application of impacts on the contents of SMBC and SMBN in croplands in China during 1990 and 2017, were collected (336 for SMBC and 222 data for SMBN from individual study). The meta-analysis was used to quantify the magnitude of manure application impacts on the contents of SMBC and SMBN at three aspects: Climatic regions, land use types and soil pH levels.【Result】At national scale, the contents of SMBC and SMBN in manure applied soils were significantly increased by 128.1% and 70.2% when compared with no fertilizer (CK), respectively, while those were increased by 57.1% and 34.2% when compared with mineral fertilizer (NPK), respectively. The increments of SMBC and SMBN contents improved by manure in subtropical monsoon climate (66.7% and 57.5%, respectively) were significantly higher than those in temperate continental climate (26.0% and 20.9%, respectively) and temperate monsoon climate (37.0% and 56.7%, respectively) compared with NPK. Furthermore, manure application could significantly increase the contents of SMBC and SMBN in paddy soils (69.1% and 67.1%, respectively) compared with NPK, which were higher than those in upland (34.7% and 26.4%, respectively) and upland-paddy soils (50.2% and 63.9%, respectively). For the neutral soils (6＜pH＜8), the increment of SMBC and SMBN contents by 64.4% and 63.7% in the treatment with manure applied were higher than those in the alkaline (pH＞8, 29.4% and 21.9%) and acidic soils (pH＜6, 44.4% and 45.5%) compared with NPK, respectively. In addition, the correlation analysis showed that the contents of SMBC and SMBN were positively correlated with annual carbon and nitrogen input from manure, respectively. 【Conclusion】Overall, the application of manure can dramatically improve the contents of SMBC and SMBN, indicating manure supplementation provided sufficient carbon and nitrogen for microbial growth and reproduction, and nutrient retention. Nevertheless, the effect of manure application on the contents of SMBC and SMBN relative to CK and NPK were significant different among climatic regions, land use types and soil pH levels. Therefore, climate types and soil conditions should be taken into consideration for applying manure in different regions in China.

【Objective】The objective of this study was to explicit the effect of inherent soil productivity and different fertilizer measures on maize (Zea mays L.) yield in southwest China, so as to provide scientific basis for improving soil fertility and proper fertilization of the maize belt in southwest China.【Method】Based on 508 maize field trials in southwest China since 2006, we have chosen 5 treatments, including non-fertilizing control (CK), nitrogen and phosphate (NP) fertilizer, nitrogen and potassium (NK) fertilizer, phosphate and potassium (PK) fertilizer, and NPK fertilizer (NPK), to measure maize yield and nutrient absorption, and to analyze the yield, soil and contribution characteristics of inherent soil productivity, as well as yield response and agronomic efficiency. And we evaluated the relationship between the soil foundation and maize yield (or yield gap) by using the line fitting and boundary line method, and assessed the effect of the soil foundation on the stability and sustainability of fertilizer-induced yield by using the stability index and the sustainability index in the maize planting area.【Result】The maize yield based on soil fundamental fertility in the southwest region ranged from 3.9 to 4.7 t·hm^-2 (average: 4.4 t·hm^-2). Fertilization could significantly increase the maize yield. The average yield in the fertilizer (NPK) application area was 7.7 t·hm^-2, which increased 3.3 t·hm^-2 than the yield based on the soil fundamental fertility. The results based on the boundary analysis showed that the high yield potential was 11.5, 12.7, 12.6 t·hm^-2 (average11.7 t·hm^-2) in Chongqing, Sichuan and Guizhou, respectively. The contribution rate of maize yield and fertilizer contribution averaged 57.1% and 42.9%, respectively; the contribution rate of soil productivity increases with the increase yield based on inherent soil productivity. The effects of fertilizers on the increase of maize yield from high to low were as followed: the nitrogen fertilizer > phosphate fertilizer > potash fertilizer in southwest China. The fitting line decision coefficient between maize realistic productivity and inherent soil productivity in Chongqing, Sichuan, Guizhou and the entire southwest was 0.356, 0.356, 0.393 and 0.434 (P<0.001), respectively. And with the increase of inherent soil productivity, the fertilizer-induced yield gap decreased, whereas the stability and sustainability of the yield increased. 【Conclusion】Improving inherent soil productivity could increase the maize yield and increase the stability and sustainability of the yield, reduce the dependence of maize on fertilizer, and promote the high and stable yield of maize in the southwest China. 

【Objective】This study investigated the effects of different dosage of special controlled release urea (CRU) on the yield and nitrogen (N) uptake of winter oilseed rape in different areas. Our aim was to evaluate the suitable rate of the special CRU for oilseed rape and provide the basis for guiding light simplification of oilseed rape production.【Method】Field experiments were conducted in Hengyang (Hunan Province), Jiujiang (Jiangxi Province), and Wuxue (Hubei Province) during the period of 2015-2016, investigating nutrient release and fertilization effects of the special CRU. Each site included 5 nitrogen application rates being 0, 60, 120, 180 and 240 kg N·hm^-2, respectively.【Result】Field bagging experiment showed that the release time of special CRU was about 150 days, with the accumulative release amount of 83.4%, which coincided with the N demand of oilseed rape. The application of special CRU could control the harvest density of winter rapeseed, increasing the number of pods per plant and seed number per pod. Compared with no N treatment, the number of pods per plant and seed number per pod increased 15.0-81.5 pods per plant and 0.2-2.4 seeds per pod, respectively. Harvest density changed the coordination group and individual with N fertilizer variation. Oilseed rape production performed the highest grain yield when applying 180 kg N·hm^-2 among the sites, which increased by 1 118 and 1 088 and 2 049 kg·hm^-2, Compared with the without N treatment, respectively. By fitted with linear and platform model, optimal special CRU dosages were 174, 180 and 192 kg N·hm^-2 in Hengyang, Jiujiang and Wuxue, respectively. The biomass, N concentration and N accumulation of aboveground biomass were significantly increased with the application of the special CRU. With the increase of N application rate, the proportion of N in the stem was raised gradually, and the proportion and distribution of N in the seed decreased, while the ratio of N distribution in the shell kept about 10%. The nitrogen use efficiency (NUE) was different in different periods. The NUE was 50.69%-56.89% at flowering period, 39.39%-46.71% at harvested period, and only 9.20%-23.45% at seedling stage, respectively. At seedling and flowering stages, the NUE showed increase first and then decrease with N application rate increase, reaching the maximum when the amount of the special CRU dosage was 180 kg N·hm^-2. However, at harvest stage, the NUE reduced with the increase amount of nitrogen application. 【Conclusion】The special CRU for winter oilseed rape could improve N uptake and promote the growth and development of rape in each growth period, especially in regulating the harvesting density, increasing the pod number per plant and seed number per pod, and eventually enhancing the rapeseed yield. The recommended amount of special CRU was 180 kg N·hm^-2 among the sites.

【Objective】In order to reveal the molecular mechanism of sugar-apple flower development, the function of differential expression proteins among four flower developmental stages were studied by using an approach of plant proteomics. 【Method】Flower samples were collected at four flower developmental stages: floral bud stage, bud stage, the mature flowers with partially opened petals stage and mature flowers with opened petals stage. The expressed proteins of flowers in four stages were detected using two-dimensional gel electrophoresis (2-DE) technology. All expressed proteins and their functional annotation were analyzed by MALDI-TOF-MS mass spectrometry .【Result】The results of protein profiling showed that there was more than 800 protein spots in each gel electrophoresis and 50 of them showed differences in different stages of sugar apple flowers. 36 proteins were identified by spectrum analysis as well as MASCOT online retrieval. These proteins could be divided into 7 functional categories, including respiration and energy metabolism (11 proteins), protein synthesis and metabolism (8 proteins), transcription and translation (3 proteins), stress and defense (2 proteins), cell proliferation and differentiation (3 proteins), secondary metabolites (8 proteins) and unknown proteins (1 protein). Furthermore, the 36 identified proteins could be grouped into 20 GO classifications. Among 11 respiration and energy metabolism related proteins, three proteins (A07, C28, C42) were continuously decreased with flower development while the other four proteins (A36, A37, B13, B29) were significantly increased; among the proteins related synthesis and metabolism, two proteins (A13 and A22) expressed at low level for all four flower developmental stages, while other five proteins (B17, B20, A19, A21 and C21) expression increased significantly with the flower development. A stress and defense related protein (B32) showed highest expression in last flower developmental stage. The expression of two cell differentiation and proliferation related proteins (B27 and C57) expression was gradually increased. Five secondary metabolism related proteins expression (A06, A29, A34, C100 and C110) gradually decreased with flower development, while proteins C79 and D38 reached the maximum value in the bud stage, and then gradually decreased. 【Conclusion】Comparing the protein spectrum of the sugar-apple at four different flower developmental stages, 36 proteins were identified as differentially expressed proteins. The respiration and energy metabolism related proteins accounted as the largest proportion, such as two ATP synthase alpha subunits and pyruvate decarboxylation isozyme. Differential expression of these proteins suggested the flower development process requires a lot of energy. In addition, our study first reported two pentatricopeptide repeat-containing proteins, and the expression of them changed with the flower development process. However, the function of these proteins remains to be further study. The results suggest that energy metabolism, secondary metabolism, protein synthesis and other biological processes may be involved in the process of flowering regulation of sugar-apple.

【Objective】The effects of straw mat and other mulching materials on apple roots and leaves in different seasons were revealed, which provided a basis for the reasonable mulching in the orchard.【Method】In the spring (April 18), the materials of straw mat, agricultural carpet, horticultural fabric and transparent plastic film were mulched on the ground of 3-year-old Starkrimson apple tree (Malus domestica Borkh), respectively, the clean tillage was used as control. It was measured that the changes of root activity, nitric oxide (NO) production rate, nitrate reductase (NR) activity, nitric oxide synthase (NOS) activity in roots, net photosynthetic rate and other physiological parameters in the next mid-spring, late summer, mid-autumn and early winter. The plant growth root architecture were analyzed in autumn and winter.【Result】The changes of root activity, root NO production rate, leaf Pn and other physiological parameters were significantly different among the four mulchings in different seasons. In spring, the root activity, root NR and NOS activity, and NO production were increased after the mulching treatment, especially the transparent plastic film and agricultural carpet increased them more. In summer, they were also increased under the straw mat and agricultural carpets treatments, but were significantly reduced under transparent plastic film treatment. In the autumn, the activities of NR and NOS were increased under the four mulching treatments. In the early winter, the values of above root physiological parameters all increased significantly under the mulching of straw mat, agricultural carpet and horticultural fabric. Straw mat had more significant effects on root physiological characteristic than other mulching materials in the year except spring. The four treatments reduced the coefficient of variation of all the root physiological parameters, among which the agricultural carpet was the smallest, while transparent plastic film was the largest. The four mulching enhanced the leaf Pn in late summer, mid-autumn and early winter, improved leaf water use efficiency (WUE) in the autumn, increased the total length, diameter, volume and fractal dimension of the roots in the early winter, and promoted shoot growth and trunk thickening. The effects of straw mat and agricultural carpet mulching were more significant than other two materials. The straw mat had the most significant effects on the improvement of root physiological characteristics, and morphological structure, the increase of leaf photosynthetic characteristics and the promotion of plant growth. The effect of agricultural carpets on root fractal dimension is similar to that of straw mat, which is higher than that of horticultural fabric and transparent plastic films in autumn, and the stability of agricultural carpets on the changes of root physiology is most prominent. The effects of horticultural fabric on leaf Pn were less than that of straw mat in late summer and mid-autumn, and its effect on root physiological parameters was less stable than that of agricultural carpet. The transparent plastic film reduced the root activity in the late summer and mid-autumn. In the four treatments, transparent plastic film had the least effect on leaf WUE as well as on plant growth in autumn, and the stability on root physiological changes was also minimal.【Conclusion】From the beneficial effects of the four mulching materials on root activity, root architecture, photosynthesis, water use efficiency, plant growth and root physiological changes, straw mat is the best.

【Objective】In order to improve fruit quality through the soil and fertilizer management technology, this study explored the relationship between fruit and leaf nutrients, soil fertility and fruit quality (total phenols, flavonoids, anthocyanin, glucose, fructose, soluble sugar) of V. uliginosumin the Greater Xing'an Mountains, screened the main soil fertility factors affecting the accumulation of flavonoids and saccharides in the fruit of V. uliginosum by influencing the content of mineral elements in the leaf. 【Method】The V. uliginosum which grew in three site types were used as material. The three site types included Meadow bog with soil layer type, meadow bog Carex soil layer type and mountain slope type. The canonical regression analysis was used to study the correlation between soil fertility, leaf and fruit mineral element and fruit quality. Multivariate linear regression analysis was used to establish the regression equation, and to filtrate the main soil fertility factors which affected leaf mineral element in V. uliginosum. 【Result】The total contents of monosaccharide glucose and fructose in the fruits grew in Meadow bog with soil layer type and mountain slope type accounted for 84.20% and 95.11% of soluble sugar, respectively. Glucose and fructose were mainly accumulated at fruit maturity in terms of soluble sugar. The phenomenon only occurred in Meadow bog with soil layer type and mountain slope type, the total content of monosaccharide glucose and fructose in the fruits grew in meadow bog Carex soil layer type was measured only 56.95% of soluble sugar. The contents of total phenol and anthocyanin showed significantly differences in three different site types (P＜0.05). The canonical regression analysis indicated that the content of total phenol showed high significant positive correlation with the contents of Ca, Mg, Fe, Mn in fruit, and significant negative correlation with P element. Fruit K and Zn contents significantly influenced fruit quality characteristics, and K content had high significant positive correlation with flavonoid and significant positive correlation with anthocyanin and soluble sugar, the content of Zn was highly negatively correlated with flavonoids, anthocyanin, glucose and fructose in fruit. The contents of Ca and Fe in leaves had significantly positive and negative correlation with flavonoids, anthocyanin, glucose and fructose, respectively, but Ca in leaf had high significant correlation with Zn. Soil fertility had weak relation to the indexes of fruit quality. The contents of N, P, K in leaf were significantly positively correlated with N, P, K in fruit. P in leaf had high significant correlation with K in fruit, Zn in leaf was negatively correlated with Ca and Fe in fruit. Only Mg and Cu in fruit were significantly correlated with soil nutrients, and the soil nutrients mainly affected the leaf mineral content. Besides, the relationship between mineral elements in leaf and soil fertility was complex. Multivariate linear regression analysis indicated that soil pH had the greatest effect on mineral element in leaf, followed by soil organic matter. The content of N, P, K, Mn in leaf increased as the increase of soil organic matter, but the content of Zn decreased. 【Conclusion】The key technical strategies for soil management of V. uliginosum are to improve soil organic matter and ammonium N content, and enhance acidity in soil. Improving the content of K, Ca, Mg, Fe, Mn contents and reducing the content of Zn element in fruit are important measures to improve the fruit quality of V. uliginosum.

【Objective】 Phloridzin oxidation product 2 (POP2) is a final polyphenol oxidation product generated by enzymatic oxidation in the process of fruit juice, and it has an important impact on the browning and deterioration of fruit juice. In order to detect POP2 effects during process and storage of apple juice, the phloridzin polyphenol oxidase reaction system was established, POP2 was separated and purified, structural characterization was analyzed. 【Method】 The three reaction factors of pH, temperature and substrate concentration were tested first, and then enzyme reaction in ethanol solution were studied, and content changes of phloridzin, intermediate products, POP2 during oxidation process were detected by HPLC method. The POP2 was isolated and purified by ethyl acetate extraction, anhydrous ethanol desalting and recrystallization, the structure of POP2 was characterized by the methods of ESI-MS and IR.【Result】 The optimal conditions for the enzymatic oxidation of phloridzin were pH 6.5, 35℃, substrate concentration 3 mg?mL^-1. The addition of different concentrations of absolute ethanol had a significant increase in the rate of enzymatic oxidation of phloridzin, the highest reaction conversion rate was 2.4 times at 20% ethanol concentration. The color of the phloridzin reaction fluid changes from slightly yellow, bright yellow, orange to orange-red at the beginning, middle and final reaction stage. The HPLC results showed that the conversion rate of phlorizin was 90.2% when the substrate concentration was 3 mg?mL-1 and the reaction time was 48 h. Intermediates X1 and POP1 were almost close to trace, the accumulated POP2 was stable. The residual phloridzin in the reaction solution could be removed by ethyl acetate extraction. The purity of 96.8% POP2 was obtained by anhydrous ethanol desalting and recrystallization from methanol. The molecular weight of POP2 was 467 by positive mode ESI-MS analysis, molecular formula is C₂₁H₂₂O₁₂. IR results showed that POP2 had characteristic ether, ketone, benzene ring and carboxyl functional groups, and it was consistent with the structure of the predicted phlorizin oxidation product structure. 【Conclusion】 The major oxidation products of phloridzin in enzymatic system is POP2, POP2 content can be established a landmark test indicators in apple juice browning and deterioration.

The introduction of Clementsian succession theory in early twentieth century represented a substantial advance in rangeland ecology. Succession theory as a central concept of equilibrium ecology had profound influence on development of rangeland science and natural resource management models. However, equilibrium ecology and the steady-state management model received severe criticism in 1970s and 1980s. On one hand, nonlinear vegetation dynamics was recognized in rangeland ecosystem research, which is inconsistent with the interpretation of the traditional succession and steady-state management. On the other hand, research in other parts of the world indicated that the rangeland concepts and range models developed in United States did not well apply to the ecosystems in Africa and Asia where the prevailing environments are characterized by frequent disturbances and alternative conceptual frameworks are called for to provide more realistic, accurate interpretations of range vegetation dynamics and scientific support to natural resource management. In this context, equilibrium ecology emerged in response to the dissatisfaction of the prevailing ecological theory. In particular, an ecosystem-level research in east Africa presents a view of pastoral ecosystems that are nonequilibrial but persistent (persistent nonequilibrium model), and further research resulted the recognition of the importance of relative proportion of key resource in the dry/cold season as the determinant of animal numbers and their potential impacts on vegetation. The state and transition models which emerged in 1980s represented an important alternative conceptual framework and were applied in 1990s to rangeland assessment as a replacement of range condition in USA. Resilience is currently replacing nonequilibrium as the dominant ecological concept because ecosystems that were previously considered nonequilibrium is now more appropriately interpreted as multiple equilibria in many cases. The advances in rangeland ecological theory have been accompanied by parallel progression of rangeland management model, notably a transformation of the role of human from resource users to resource stewards. The rangeland models in twentieth century were generalized as steady-state management with the overall goal of maximizing sustainable production of forage and livestock. The application of resilience as the most recent and important ecological advance has been extended to coupled social-ecological systems, leading to the development of the concept and procedures of adaptive management. Currently the above described models are in application to a greater or less extent and synthesis of different models for rangeland assessment and management will help develop improved framework for complex, adaptive social- ecological systems.

【Objective】 Root improvement is one of the key factors to improve stress resistance and yield of wheat. Root architecture related genes, homoeologous TaDRO, are cloned from cultivars with different root phenotypes. Molecular markers are developed to detect its relationship with important agronomic traits of wheat. which could provide technical support for wheat improvement. 【Method】 Polymorphic sites of TaDRO-A, -B and -D were detected in 21 common wheat accessions with high diversity. Physical locations of three homoeologues were determined based on the newest genome sequence of Chinese Spring. Molecular markers were developed according to the polymorphic sites at TaDRO-5A and -5B. Association analysis between genotypes and phenotypic traits were carried out in a natural population of 323 accessions. 【Result】 The three homoeologous genes of TaDRO-A, -B and -D were cloned. TaDRO-A, -B and -D were located on chromosomes 5A (426.15 Mb), 5B (381.00 Mb) and 5D (327.60 Mb), respectively. Three SNPs were detected at TaDRO-A among 21 accessions and two haplotypes were formed, Hap-5A-A and Hap-5A-C. A molecular marker, TaDRO-5A-KASP, was developed based on the SNP located at position of -2271 bp in the promoter region. Thirteen SNPs and one InDel in the promoter region, four SNPs in the coding region were detected at TaDRO-5B, formed two haplotypes, Hap-5B-Ⅰ and Hap-5B-Ⅱ. The marker TaDRO-5B-InDel was developed based on the Indel at position of -300 bp. Association analysis showed that haplotypes of TaDRO-5A were significantly correlated with plant height (PH), thousand kernel weight (TKW) and root growth angle (RGA). The genetic effects on Hap-5A-A showed RGA and TKW increasing, and root depth and PH decreasing, while those on Hap-5A-C exhibited the opposite effect. The effects of Hap-5B-Ⅰ exhibited root depth and PH increasing, and TKW decreasing, while those of Hap-5B-Ⅱ were the opposite. Hap-5A-C and Hap-5B-Ⅰ were favored haplotypes in landraces while they were non-favored ones in modern cultivars. The frequencies of Hap-5A-C and Hap-5B-Ⅰ in arid and semi-arid areas were higher than those in wet areas in China. Hap-5A-C was favored haplotype in dry regions worldwide. Frequencies of Hap-5A-A and Hap-5B-Ⅱ were increasing in breeding process, respectively.【Conclusion】 Hap-5A-C and Hap-5B-Ⅰ are associated with deeper root, higher PH and lower TKW, whereas Hap-5A-A and Hap-5B-Ⅱ behave the opposite. Wheat cultivars showed root depth and plant height decreasing in breeding process due to development of irrigation system and nitrogen industries. The developed molecular markers might be used to select the ideotypes of cultivars for higher efficiency use of water and nitrogen.

【Objective】 High salt stress is one of the main factors affecting crop yield. Setaria italica L. is characterized by its strong tolerance to stress. Therefore, screening salt tolerant related genes from millet is important for salt stress tolerant improvement of crops through genetic transformation.【Method】 The expression profile of AP2/ERF like gene SiANT1 were analyzed in Yugu 1 at seedling stage under high salt, low nitrogen and PEG simulated drought conditions. Millet gene SiANT1 was transformed into rice Kitaake by agrobacterium-mediated transformation method. overexpressing SiANT1 rice seeds and wild type Kitaake were digested with 0.9% saline and tap water, respectively. The phenotypes of germinating stage and germination rate were observed. Rice seedlings were treated with 0.9% NaCl in Hogland nutrient solution for 10 days and then dried at 65℃ for 48 hours dry weights of all the rice overexpressing SiANT1 and wild type (WT) plants were analyzed. At the same time, phenotype of all plants was analyzed in the field and all plants were irrigated once with 0.9% saline before rice pregnancy. Under the similar salt treatment condition, single seed grain weigh plant height and tiller number per plant of the overexpressing SiANT1 rice lines and wild type were also analyzed. The real time-PCR method was used to verify the expression of SiANT1 and its possible downstream genes in transgenic rice lines.【Result】 Setaria italica L. SiANT1 protein (XP004985124.1, SiANT1) belongs to the AP2 subfamily and has a close genetic relationship with sorghum (XP021318293.1, SbANT1) and maize (XP008658933.1, ZmAP2).The gene of SiANT1 was induced by high salt stress (100 mmol·L^-1 NaCl) in Yugu 1. The SiANT1 was ligated to LP047 1118-Bar-ubi-EDLL vector, Agrobacterium transformation method was used to transfer SiANT1 into rice genome, positive T₀ plants were screened, then breeded two generations and got T₃ seeds. Under water immersion, the germination rate of SiANT1 overexpression rice was similar to that of wild type. Germination rate was more than 90%. Under 0.9% saline immersion, the overexpression of SiANT1 was significantly inhibited. Compared with the wild type, over-expression of SiANT1 rice seeds dew white was delayed, but finally(treatmented for 120h) germination rate was more than 80% .After treatment with 0.9% NaCl at seedling stage in greenhouse, the dry weight of single plant overexpressing SiANT1 increased 14.11%-37.42% more than that of WT, which had significant difference at the 1% level. The grain weight of transgenic rice overexpression SiANT1 in field increased 56.12%-76.58% higher than that of WT, which had significant difference at the 5% level, the number of tillers per plant and plant height increased, but there was no significant difference with the wild-type. Semi-quantitative RT-PCR analysis showed that all three rice lines overexpressing SiANT1 expressed SiANT1 at the RNA level. Real time-PCR results showed that the relative expression level of SiANT1 in three rice lines overexpressing SiANT1 was different but significantly increased compared with that of the recipient, and the relative expression levels of endogenous salt-tolerance-related genes OsSOS1 and OsZFP182 were 1.1-1.7 fold and 1.6-2.3 fold respectively higher than that of the recipient.【Conclusion】 It has been confirmed that OsSOS1 and OsZFP182 are salt tolerance related genes. SiANT1 gene has certain salt tolerance. Overexpression of SiANT1 in rice may increase salt tolerance by increasing the expression of downstream genes OsSOS1 and OsZFP182.

Lodging is a common problem during maize production. Maize harvested at physiological maturity stage in traditional maize production. Previous researches about maize lodging also focused on stalk development process and some stage before the physiological maturation. There was less lodging research after physiological maturity. Mechanical grain harvest usually was carried out two to four weeks after the physiological maturity. Lodging made mechanical grain harvest become difficulty and increased harvest costs, and it also increased grain losses and decreased the grain quality. Maize lodging was a limiting factor in application of mechanical grain harvest technology. This paper reviewed the physiological changes in the maize senescence process and the influences factors on maize lodging, and proposed the measures and suggestions about improving maize lodging resistance during mid and late stage. Analysis showed that, natural senescence of maize from physiological maturity to harvest decreased activity of leaves, stalk and root, and made all of stalk moisture, water-soluble carbohydrate content, hemicellulose content and total structural carbohydrate content decline. These resulted in cell wall thinning, cell gap widening, and stalk strength and disease resistance decrease. The enzymatic activity of PAL, POD and PPO was low, which made the disease resistance decline. The stalk rot pathogen produced cell wall degrading enzymes to decompose cellulose and collapse the cells in stalk. The fungal hyphae flew through the plasma membrane and entered into epidermis cell, cortex and vascular bundle tissue. The stalk rot then increased the speed of stalk dehydration and drying shrinkage, and degraded the pith tissue. Maize stalk became hollow, softening and rot. This decreased stalk quality. Higher grain and full mechanization technologies required high population and delayed harvest to grain dehydration in the field. These accelerated and extension the aging process of maize, further decreased the stalk quality and disease resistance, and increased the lodging risk of maize after physiological maturity. In order to resolve the lodging problem and to accelerate development and promotion of maize mechanical grain harvest technology in China, we suggested that: (1) Theoretical research of maize lodging during late stage should be strengthened; (2) Germplasm creation should be strengthened to breed new maize cultivars with early-maturity, density-tolerant, high rate of grain dehydration, and strong stress resistance; (3) Common methods should be developed to obtain high-quality maize populations and reduce lodging during late stage including constructing a high-quality plow layer, suitable cultivars for grain mechanical harvest, rational close planting, scientific irrigation and fertilization, application of plant growth regulators, and insect-disease prevention; (4) Integration countermeasures should also be established according to ecological conditions in different maize regions.

【Objective】 The high grain dehydration rate and the low grain moisture content at harvest are two ear characters, which can be established for maize mechanical grain harvesting. Ear characters are decided by genes and have close relationship with grain dehydration. This internal relationship and the key ear characters that can characterize the traits of grain dehydration remain unknown, which are of great significance for breeding and screening of suitable varieties. 【Method】 The report researched on a total of 22 main cultivars of summer maize in HuangHuaiHai plain, and their ear characters were divided into 41 parameters covering bract, grain, cob and ear-pedicel. In 2015 and 2016, these parameters were measured and were used in correlation analysis with five grain parameters describing the dehydration rate, including the grain dehydration rate before physiological maturity (GDRbpm), the grain dehydration rate after physiological maturity (GDRapm), the total grain dehydration rate (GTDR), the grain moisture content at physiological maturity (GMCpm) and at harvest (GMCh). 【Result】 These 41 parameters were significantly different between the 22 cultivars, and there were some parameters significantly linked to grain dehydration. The bract length had a significantly negative relationship with GDRapm and a significantly positive relationship with GMCh. The value of “bract length/ear length” had a significantly negative correlation with GDRapm. The ear angle was positively correlated to GTDR at a significant level. The cob moisture content at physiological maturity had significantly positive relationships with GMCpm and GMCh. The grain number per ear was positively correlated to GDRbpm and GTDR at a significant level. The value of “ear length/grain number per row” had significantly positive relationships with GDRbpm, GDRapm and GTDR and had a significantly negative relationship with GMCh. The 100-grain dry weight at physiological maturity was negatively correlated to the grain moisture content at the significant level. There were no significant correlations between the other ear parameters and the five grain dehydration parameters.【Conclusion】 The current cultivars had different ear characters in HuangHuaiHai plain. These parameters contributed to grain dehydration rate, including the shorter bract, the lower moisture content of cob at physiological maturity, the larger ear angle, the fewer grain number per ear, and the smaller grain, which could be used in breeding and screening of mechanical grain harvest cultivars.

【Objective】 The objectives of this study were to investigate the variation of maize cob mechanical strength and its influence on kernel broken rate to provide a theoretical basis for improving maize harvest quality. 【Method】 Maize cultivars selection experiments were conducted in large area field. The same combine harvester and operating personnel were used in different harvest date to study the variation regularity and influence factors of maize cob mechanical strength during late growth period, to analyze the relationship between cob mechanical strength and kernel broken rate. The cob morphology, moisture content, dry matter accumulation, mechanical strength characters, kernel moisture content, and broken rate were investigated in this research. 【Result】 The results showed that, as harvest date delayed, maize kernel and cob moisture content decreased, and the bending strength of 8 cm and whole cob, and kernel broken rate showed a trend of decrease first and then increase. When kernel moisture content was below 20.1%, kernel broken rate increased exponentially with the increase in cob strength. When kernel moisture content was higher than 20.1%, kernel broken rate increased exponentially with the increase in bending strength of whole cob, and there was no significant relationship between kernel broken rate and bending strength of 8 cm cob. The bending strength was significantly and negatively correlated with moisture content of cob. In contrast, bending strength were significantly and positively correlated with penetration strength, dry weight, dry weight per unit length, and dry weight per unit volume. Path analysis showed that dry weight per unit length had the greatest effect on bending strength of cob. 【Conclusion】 Cob mechanical strength is one of the important factors affecting kernel broken rate in maize grain harvest. The dry matter accumulation and moisture content are important factors affecting the mechanical strength of the cob during late stage.

【Objective】 Nowadays, the higher grain moisture content at harvest limits the popularization and application of the mechanical grain harvesting technology. Maize grain filling process is accompanied by grain dehydration process after pollination, however, the relationship between these two processes remains a challenge. We used different maize cultivars to study the characters of the two processes and the relationships between them, which provided support for breeding and promotion of the harvesting technology. 【Method】 Field experiments were conducted in Xinxiang, Henan in 2015 and 2016. A total of 22 cultivars were studied and the controlled pollination was applied in every cultivar. In 2015, the sampling time was from the 26th day after pollination to November 14th. In 2016, the sampling time was from 11th day after pollination to October 17th. We measured dynamic changes of grain moisture content (MC), moisture (M), dry weight (DW) and fresh weight (FW) before and after physiological maturity to establish the relationships between these indexes and the accumulated temperature after pollination (T) by equations. Based on these equations, the grain dehydration process and the filling process were clarified. Then, we developed the relationship between these two processes by the correlation analysis. 【Result】 Results showed that T had the significant non-linear relationships with MC, M, DW and FW. Among them, the relationship between MC and T of 22 maize cultivars could be described by the Logistic Power regression model. The MC dropped to 28% when the T reached average 1 357°C·d, changing from 1 126 °C·d to 1 646 °C·d between cultivars. The average T was 1 480°C·d for 25% MC, changing from 1 218 °C·d to 1 810 °C·d. Dynamic change of MC could be divided into two stages based on the changes of DW and M. The first stage was from the start of grain growth to the end of linear filling process, in which the decreasing MC was mainly decided by the fast dry matter accumulation. The second stage followed the former ending to the harvest time, in which the decreasing MC was owned to the decreasing M. The correlation analysis showed that there was a significant negative correlation between the MC at physiological maturity and the filling days, and the T from pollination to physiological maturity in 2015 while the relationship was not significant in 2016. There was no significant relationship between the filling rate and the grain dehydration rate before physiological maturity, similar to the grain dehydration rate after physiological maturity and the total dehydration rate. 【Conclusion】 Our study found that the Logistic Power regression model had a good predictive stability to establish the relationship between MC and T. We proposed that MC was decided by the grain filling rate and the grain moisture loss rate respectively at different stages. Thus, breeders should not only pay attention to grain filling characters and maturity time, but also concern about the grain dehydration characters when evaluate suitable cultivars for the harvesting technology.

【Objective】 Yield and production efficiency are two equally important things under the condition of large-scale production. The sowing time and the harvesting time can be prolonged by various combinations of sowing date and different maturity cultivars, thus improving the utilization efficiency of combine machine and the maize production efficiency.【Method】 In this study, three maize cultivars, including KWS9384, Xinyu77 and M751, with different growth stages were selected to monitor the dynamic process of grain moisture content from 2015 to 2017. The predictive relationship model between the grain moisture content and the accumulated temperature (> 0°C) after pollination was established to analyze the key growth nodes of different combinations based on the local meteorological data.【Result】 The results showed that there were significant differences of grain yield and suitable sowing date between cultivars. The early maturity cultivar KWS9384 had a longer time of sowing and harvesting but a lower yield compared with the late maturity cultivars. The late maturity cultivars Xinyu77 and M751 both had higher yields but they needed more time to finish physiological maturity and to dry down grain to meet grain mechanical harvest. The combination plans of late maturity cultivar/early sowing or early maturity cultivar/late sowing could be used to coordinate the relationship between yield and grain moisture content, thus extending the sowing time and the grain harvesting time.【Conclusion】 This paper studied on the suitable sowing time and harvesting time of different maturity cultivars and gave the combination principle of cultivar and sowing date under the background of high yield and high efficiency production. The principle could maximize the utilization efficiency and benefit of combine machine under the specific ecology and production condition. This study provided the new information regarding the relevant researches and application of the maize grain mechanical harvesting technology.

【Objective】 Canker disease is one of the most devastating diseases that cause serious damages to citrus. It is more likely to occur under high temperature. The objective of this study is to elucidate the mechanism underlying the disease incidence at high temperatures, reveal its metabolic changes, and to provide important theoretical guidance for controlling the disease using certain chemicals.【Method】 Sweet orange (Citrus sinensis), which is sensitive to canker disease, was used as the experimental material. The sweet orange plants were pre-cultured for 3 d at either 21℃ or 30℃ prior to inoculation with Xanthomonas citri subsp. citri (Xcc), followed by evaluation of disease incidence. Expression of four defense-related genes, including AOS (allene oxide synthase), CHI (chitinase), GPX (glutathione peroxidase) and PR4A (pathogenesis-related protein 4A), in the plants pre-cultured at the two temperatures was assessed by semi-quantitative RT-PCR. Meanwhile, endogenous polyamines (putrescine, spermidine and spermine) in the plants pre-cultured at the two temperatures were also analyzed by HPLC. In addition, sweet orange plants were treated with exogenous spermidine (0.4 mmol·L^-1), using water treatment as a control, before Xcc inoculation. Disease incidence and index of plants treated with either spermidine or water were compared, while endogenous polyamine contents and expression levels of defense-related genes (AOS, CHI, GPX and PR4A) in response to spermidine or water treatment were assessed. 【Result】 After inoculation with Xcc, it was found that plants pre-cultured at 21℃ exhibited a lower cankder disease incidence at the early stage when compared with the plants pre-cultured at 30℃. On the 10th day, the incidence of the two treatments was similar. HPLC analysis showed that content of the three free polyamines (putrescine, spermidine and spermine) in plants pre-cultured at 21℃ was significantly higher than that in the plants pre-cultured at 30℃. In addition, RT-PCR analysis indicated that the transcript level of three defense-related genes, CHI, GPX and PR4A, in plants kept at 21℃ was higher than that from 30℃, while there was no significant difference in AOS expression between the two groups. Exogenous application of spermidine remarkably enhanced levels of endogenous putresicne and spermidine, reduced disease incidence and index in comparison with water treatment. Spermidine treatment reduced the disease incidence by 45% and in comparison with the control after 14 days of inoculation. In addition, the disease index of the spermidine-treated samples was 4.8 lower than that of the control. Meanwhile, the phenotype indicated that the control displayed more serious symptom than that of spermidine treatment. Moreover, spermidine treatment could up-regualte mRNA abundances of all four defense-realted genes, including AOS, CHI, GPX and PR4A. 【Conclusion】 Sweet orange displayed susceptibility to citrus canker at high temperature, and the potential mechanisms underlying this phenomenon may be ascribed to inhibition of defense-related genes and suppression of polyamine biosynthesis. Exogenous polyamine treatment conferred enhanced tolerance to citrus canker by upregulating defense-related genes and triggering disease resistance response. Taken together, high temperature is one of the environmental factors accounting for outbreak of citrus canker disease, and polyamines are conducive for improving tolerance to citrus canker disease.

【Objective】 The objective of this study is to determine the antimicrobial activity of volatile organic compounds (VOCs), produced from tobacco rhizosphere soil Bacillus pumilus AR03 strain, and to analyze its main components.【Method】 The antifungal effect of VOCs on the colony, mycelium growth and spore germination of Phytophthora parasitica var. nicotianae and Alternaria alternata was determined by a double Petri dish assay and cavity slide method. The control effect of VOCs on tobacco black shank and brown spot by leaf inoculation was determined in vitro. VOCs were collected by head-space solid phase microextraction (HS-SPME) and identified by gas chromatography-mass spectrometry (GC-MS). Retention index (RI) and internal standard (IS) 1-pentadecence were used for qualitative and quantitative analysis.【Result】 VOCs released from B. pumilus AR03 strain had certain inhibitory effect on the two target pathogens, which showed that the mycelium of P. parasitica grew slowly and thinned, branches increased and twisted, and broke. The mycelium of A. alternata was deformed and no conidial pedicle was produced on the mycelium. Most of the inclusions gathered together and caused the mycelium to dry and constricted. Growth of exposed fungus colonies was inhibited by VOCs, the inhibition rates of VOCs were 56.21% and 59.23%, 64.75% and 59.86%, 66.13% and 61.10%, 67.04% and 70.00%, respectively, against P. parasitica and A. alternata cultured in sealed plates for 2, 4, 6 and 8 d. When the zoospores of P. parasitica and ascospores of A. alternata exposed to these volatile components for 6 h, the germination was delayed and the growth was slow. The number of sporocyst produced by P. parasitica obviously reduced. Most conidiophores of A. alternata expanded abnormally as cystic structure, indicating the fungicidal nature of the volatiles. Moreover, VOCs could significantly inhibit the disease severities of tobacco black shank and brown spot on leaves tests. Direct fumigation for 40 h and 80 h, black shank disease incidence was 92.50% on control and 70.83% on leaves treated by VOCs, the inhibitory of spot expansion was 62.35%. Brown spot disease incidence was 88.33% on control and 60.80% on leaves treated by VOCs, lesions expanded slowly and inhibitory rate was 65.75%. SPME GC-MS analysis showed that seven components of the volatiles were identified, all of which are sesquiterpenes with C₁₅H₂₄ structure. They are dihydrocurcumene (CAS NO. 1461-02-5), (E)-β-famesene (CAS NO. 18794-84-8), γ-curcumene (CAS NO. 451-55-8), α-zingiberene (CAS NO. 495-60-3), π-bisabolene (CAS NO. 495-61-4), β-sesquiphellandrene (CAS NO. 20307-83-9) and γ-E-bisabolene (CAS NO. 53585-13-0). When AR03 was cultured for 1 d, the relative content of β-sesquiphellandrene was the highest (80.64%), followed by (E)-β-famesene and α-zingiberene, the relative content was 7.20% and 6.67%, respectively. With the extension of culturing time, the species of each component were the same, but the relative content was different. Except for dihydrocurcumene, the content of other components showed a decreasing trend, when cultured for 6 d, other ingredients decreased more than 50%, besides dihydrocurcumene keeping relatively stable. 【Conclusion】 VOCs produced by B. pumilus AR03 could develop an additive antifungal effect against fungal pathogens on tobacco. B. pumilus AR03 has potential as an important microbial resource for developing antifungal metabolites and new drugs.

【Objective】 Microbes play the key role of switcher in soil nutrient cycling, the aim of this paper was to study the effects of soil microbial community structure by long-term fertilization of biochar and biochar-based fertilizer, and to provide theory reference on reasonable administration of different organic fertilizers, contrasting with traditional organic fertilizer (corn straw and piggery manure compost) in the meantime. 【Method】 This research was based on the long-term experiment of soil improvement of brown soil in Shenyang Agricultural University (began in 2009). The changes of soil physic-chemical properties, soil microbial community structure and their relationship by long-term organic fertilizer plus NPK fertilization were studied by PLFA and correlatively analysis. Soil samples were collected from treatments as farmland with biochar-based compound fertilizer (BF) alone and farmland with piggery manure compost (PMC), corn straw-returning (CS), biochar (BIO) combination of NPK fertilizer, respectively. 【Result】 Soil pH of PMC and BF were higher than BIO significantly; total N (TN) of PMC was significantly higher than BF and CS, which of BIO had no significant difference with PMC; soil organic matter (SOM) of PMC was significantly higher than that of BF and BIO; moisture content (MC) of PMC was the highest of all treatments; total K (TK) of all treatments had no significant difference. Total PLFAs of PMC was significantly higher than other treatments, but there were no significant differences among others; bacteria PLFAs of PMC was the highest of all treatments, which of BF was significantly lower than BIO and CS; fungi, gram-positive, gram-negative PLFAs of PMC were significantly higher than BIO, which of BF had no significant difference with PMC; actinomyces PLFAs of PMC was higher than CS significantly, there were no significant differences between BIO and BF. The result of analysis showed that Shannon-Winner richness index (H) and the fungi/bacteria PLFAs ratio of BF was higher than BIO significantly, the gram- positive/gram-negative PLFAs ratio of BF and PMC were lower than BIO significantly. The result of redundancy analysis (RDA) showed that microbial PLFA was significantly influenced (P<0.01) by soil pH, TN and SOM, and significantly influenced (P<0.05) by MC and TK.【Conclusion】 Soil physico-chemical properties were obvious improved by long-term fertilization of biochar and biochar-based compound fertilizer. Compared to PMC, farmland with BIO was bad for the growth of fungi and gram-negative microbe, and farmland with BIO and BF had different effects on soil microbial community structure, namely, farmland with BIO could increase the biomass of bacteria, while farmland with BF could increase the fungi/bacteria ratio and the diversity of soil microbial community structure. Soil pH, TN, SOM, MC and TK were the important factors which influence the soil microbe community structure in this study in the order.

【Objective】 This study was conducted to explore the response of the sugarcane yield stability, fertilizer contribution rate and N, P loss in runoff under long-term different fertilization, with an aim to provide scientific references for establishing the optimal fertilization pattern and promoting the sustainable production of sugarcane as well as the quality of agroecosystem improvement.【Method】 Four different fertilization treatments (non-fertilization (CK), optimum fertilization (OPT), application of 50% N increase based on OPT (OPT+N) and application of 50% P₂O₅ increase based on OPT (OPT+P)) were chosen from an 8-years fertilization filed experiment. The changes of annual sugarcane stem yield, fertilizer contribution rate and N, P loss in runoff were investigated. 【Result】 At the first 4 years of planting, sugarcane yield declined sharply, and then kept equilibrium around 50 t·hm^-2, while fertilization treatments showed a fluctuation in different years, and kept the same trend in the same year. Fertilization significantly increased the sugarcane yield and its stability. With an average of 8 years, sugarcane yield under fertilizer treatments was 70% higher than that under CK. However, there was no significant increase between OPT and OPT+N treatments in sugarcane yield, while OPT was higher than OPT+N treatment. There was no significant difference among fertilizer treatments in sugarcane yield stability. The soil contribution rate in sugarcane field declined sharply at the first 4 years of planting, while fertilizer contribution rate showed the opposite trend, and then both of them basically stabled at around 50%. Both of fertilizer contribution rate and agronomic efficiency in OPT treatment were significantly higher than or equal to OPT+N and OPT+P treatments. Fertilization significantly increased N and P runoff loss. Excessive application of N and P fertilizer significantly increased the corresponding N and P loss, but not N (P) fertilizer loss rate. 【Conclusion】 Excessive application of N and P not only had no advantage in sugarcane yield and its stability, but also resulted in waste of resources and increase of nutrient loss. OPT treatment was a better fertilization model for high and stable yield of sugarcane, high fertilizer contribution rate and low nutrient loss.

【Objective】 The objective of this study aimed to understand the sources of cadmium accumulated in the rice grain and to offer scientific support and best timing of agronomic measures to secure safety rice production. 【Method】 The study involved a pot hydroponic experiment with three Cd concentrations of 0, 0.2 and 0.5 mg·L^-1 by transplanting uniform rice plants at fully heading stage from a field with Cd contamination. Besides, the rice in the same field were also observed. The rice samples from hydroponic culture were harvested at maturity and those from the field were sampled at full heading stage, milk stage, dough stage and maturity. Dry weight and tissue Cd contents were analyzed for all the samples. 【Result】 The results showed that Cd accumulated in the rice grain was mainly transferred from the root and culm where Cd was stored before full heading in the Cd 0 treatment of the hydroponic culture. When available Cd was low in the soil (i.e., the treatment with rice kept growing in the paddy field), Cd accumulated in the rice grain was from both plant tissues stored Cd before heading and soil Cd uptake by rice after heading. The leaf and chaff appeared as net sources for Cd transferred to the rice grain, while the culm and root behaved as both pools for Cd accumulation and sources to the grain. When the rice grew in relatively high Cd content media (i.e., Cd 0.2 and Cd 0.5 treatments), Cd accumulated in the rice grain was mainly from direct uptake of Cd by the plant and small portions from different rice organs. 【Conclusion】 The Cd accumulated in the grain is transferred from different rice organs before heading stage and from direct uptake from soil/medium; the higher the available Cd in soil/medium, the higher Cd accumulated in the grain; only when there is no available Cd in the soil/medium, the Cd stored in different rice organs becomes the sole source of grain Cd. The culm and root are the two major locations for Cd storage and output in the rice plant. Heading to maturity stages are crucial to control Cd accumulation in rice grain and thus, are key period to secure production of safety rice if proper measures are taken to reduce available Cd in the growth medium as well as its uptake by direct root uptake and transport to the grain.

【Objective】 Identification of the OFP (OVATE family protein) genes from apple genome and analysis of gene characteristic, tissue expression pattern and response to abiotic stresses of OFP family genes in apple will be useful to the functional analysis of plant OFP genes. 【Method】 Based on apple genome database, the OFP gene family members were identified and the genes were analyzed using bioinformatics methods. A phylogenetic tree was created using the MEGA5.0 program. Gene structure and chromosomes location were carried out by MapDraw and GSDS separately. Expression pattern analysis of OFP genes in different tissues was done based on the existing microarray database and qRT-PCR. The expression of 13 MdOFPs genes was also analyzed under various stress conditions using qRT-PCR. 【Result】 A total of 28 OFP genes was systematically identified from apple genome and classified into 4 groups including 13, 6, 4 and 5 members according to the gene structure and conserved domain phylogeny relationship. All OFP genes are distributed on 13 apple chromosomes with the largest number six MdOFP on Chr12, suggesting that they have an extensive distribution on the apple chromosomes. Most of the OFP genes have distinctive expression patterns in tissues and response to NaCl and PEG treatment stresses in root and shoot, respectively. MdOFP04 and MdOFP20 were up-regulated obviously in root and shoot, while MdOFP01, MdOFP12 and MdOFP18 have opposite expression pattern in root and shoot under NaCl stress. Temperature stresses significantly regulate the expression of MdOFP and the expression of MdOFP04 and MdOFP17 were significantly increased after high temperature and low temperature stresses. 【Conclusion】 Twenty-eight OFP genes in apple were identified by genome-wide screening. They are classified into four groups and distributed on 13 chromosomes with different tissue patterns and different stress response patterns. These results will be helpful to the functional analysis of OFP genes in apple.

【Objective】 Homozygous genotype lines were obtained by anther culture of different apple pollen grains, so their botanical characteristics, biological characteristics, and their induced culture, root conditions were different. In this study, the ploidy, characteristics and root conditions of each line were observed and analyzed. Appropriate rooting conditions and good combinations of lines for selecting apple homozygous genotypes are of great significance to the innovation of apple germplasm resources.【Method】 The homozygous genotype lines of ‘Gala’, ‘Fuji’ and ‘Red Star’ were obtained by apple anther culture. The ploidy level of homozygous genotype lines was studied using flow cytometry, root and leaf morphology and root conditions of each line were observed and recorded. 【Result】 A total of 32 homozygous lines were obtained by apple anther culture. The results of flow cytometry showed that there were 1 haploid, 1 triploids, 3 tetraploids and 27 diploids. The ploidy rate of 'Red Star' homozygous genotype was the highest, about 28.57%. The root rate, root length and root number of homozygous lines were affected by IBA concentration of rooting medium. When the concentration of IBA was 2-3 mg·L^-1, the root features of apple homozygous lines were the best. The leaf number, root length, root number, plant height, leaf length/width and petiole length of each line were different. ‘Red Star’ homozygous genotype lines (DH2-1, DH0-3, DH0-4, DH0-7), ‘Fuji’ homozygous genotype line (DH1-3) and ‘Gala’ homozygous genotype lines (DH2-2, DH2-4, DH2- 12, DH2-20) have a good traits (plants are taller, roots are longer, and the number of roots and leaves are more). The survival rate of ‘Red Star’ homozygous genotype was the highest, about 28.57%. 【Conclusion】 The main ploidy of apple homozygous genotype was diploid. Compared with the diploid lines, the haploid lines had a narrow leaf base, finer petiole, the leaf color and the leaf margin were shallow, while the polyploid lines showed wider leaf base, thicker petioles, leaf color and leaf edge serrated deep.

【Objective】 The effects of different rootstock on ‘87-1’ grape photosynthetic characteristics and chlorophyll fluorescence characteristics were evaluated, and the results will provide theoretical basis for screening suitable cultivation rootstock.【Method】 Two- and three-year-old ‘87-1’ grape were grafted on eight kinds of rootstocks, including Beta, 1103P, 3309C, 140Ru, 5C, SO4, HuaPu NO.1 and KangZhen NO.1 in 2016 and 2017, and the eight kinds of rootstook-scion combinations were planted in grape center technology demonstration areas of Fruit Research Institute of Chinese Academy of Agricultural Sciences (Xingcheng, Liaoning province, east longitude 120.51° and northern latitude 40.45°). Their spacing in the rows and spacing between rows are 2.5 m×4.0 m. Double plant colonization, oblique dry horizontal dragon shape with horizontal curtain werer applied with the integration of water and fertilizer, and other management measures were routine. The Li-6400 Photosynthetic apparatus was used to measure eight rootstock-scions combinations’ light response curve, carbon dioxide response curve, temperature response curve in the cloudless morning. Before the measurement of three kinds of light curves, the optimal function leaf of different rootstock-scion combinations were selected by Li-6400 Photosynthetic apparatus. Li-6400 Photosynthesis apparatus was also used to choose the leaves with the largest net photosynthetic rate of different rootstock-scion combinations. First of all, the light response curve was measured as the carbon dioxide concentration was set at 400 μmol·mol^-1, temperature was set as 25℃, gas velocity was set at 500 mmol·s^-1, photosynthetically active radiation was set at 2 000, 1 800, 1 500, 1 200, 800, 400, 200, 100, 50, 20, 0 μmol·m^-2·s^-1 from strong to weak. Secondly, the carbon dioxide response curve was measured as the photosynthetically active radiation was set at 1 200 μmol·m^-2·s^-1, temperature was set at 25℃, gas velocity was set at 500 mmol?s^-1, carbon dioxide concentrations were set at 2 000, 1 800, 1 500, 1 200, 800, 400, 200, 150, 100, 50, 20 μmol·mol^-1 from high to low. Finally, the net photosynthetic rate curve was measured as the photosynthetically active radiation was set at 1 200 μmol·m^-2·s^-1, carbon dioxide concentration was set at 400 μmol·mol^-1, gas velocity was set at 500 mmol·s^-1, the temperatures were set at 25, 27, 30, 32, 35,27℃ from low to high. And then, the apparent quantum yield, light compensation point, carboxylation efficiency, carbon dioxide compensation point, dark respiration rate were obtained using right angle hyperbolic correction model. And the FMS-2 pulse-modulated fluorometer was used to obtain minimal fluorescence, maximal fluorescence, variable fluorescence, potential quantum yield of PSⅡ, maximal photochemical efficiency of PSⅡ in the dark. Then, variance analysis was used to compare the effects of different stock on photosynthetic parameters of ‘87-1’ grape, and Topsis comprehensive evaluation method was used to rank the eight rootstock-scion. 【Result】 The results of Topsis comprehensive evaluation showed that rootstock-scion combinations of ‘87-1’/3309C and ‘87-1’/1103P were ranked the first and second to tolerate weak light,and with the low light compensation point, high apparent quantum yield, low dark respiration rate. The rootstock-scion combinations of ‘87-1’/3309C and ‘87-1’/Huapu NO.1 were ranked the first and second to tolerate low carbon dioxide levels,and with low carbon dioxide compensation point, high apparent quantum yield. The rootstock-scion combinations of ‘87-1’/SO4, ‘87-1’/Huapu NO.1 were ranked the first and second to tolerate high temperature,and with little net photosynthetic changes at different temperatures and high net photosynthetic rate at high temperature. Furthermore, the results of variance analysis showed that the highest minimal fluorescence was found in ‘87-1’/140Ru and ‘87-1’/SO4 rootstock-scion combinations, the highest of variable fluorescence was found in ‘87-1’/1103P rootstock-scion combination, the highest of rate variable fluorescence and minimal fluorescence were found in ‘87-1’/1103P and ‘87-1’/3309C two kinds of rootstock-scion combinations. There was no significant difference of maximal fluorescence,the rate of variable fluorescence and maximal fluorescence among all 8 kinds of rootsock-scion combinations had no. 【Conclusion】 The rootstocks 3309C and 1103P can improve ‘87-1’ grape weak light tolerance ability efficiently, the rootstock 3309C and Huapu NO.1 can improve ‘87-1’ grape low carbon dioxide level tolerance ability efficiently, the rootstocks SO4 and Huapu NO.1 can improve ‘87-1’ grape high temperature tolerance ability efficiently, the rootstocks 1103P and 3309C can improve the beneficial to the enhancement of ‘87-1’ grape the primary light energy conversion efficiency.

【Objective】 This study was performed to enhance carotenoid yield, to improve nutritional value of fermentation product, and to reduce the production cost of carotenoids through optimizing solid-state fermentation substrate and fermentation conditions of Rhodotorula mucilaginosa.【Method】 In this study, Rhodotorula mucilaginosa TZR₂₀₁₄ was used as a inoculant. First, the Mixture-Design of Design-Expert software was used to design the fermentation substrate, and the contents of ingredients as followed: 50%-80% wheat bran, 6%-20% soybean meal, 3%-15% maize flour, 2%-14% rice bran, 2%-10% maize syrup, 0.4%-2.5% ammonium sulfate, 0.05%-0.5% monopotassium phosphate, and 0.03%-0.3% magnesium sulfate. Then the optimal ratio of ingredients in substrate was determined according to the carotenoid yield. Based on this result, an L₁₆(4⁵) orthogonal design was used to optimize the fermentation conditions, including inoculum (5.0%-12.5%), fermentation time (60.0-96.0 h), fermentation temperature (26-32℃), and fermentation pH (60.0%-75.0%). Finally, the number of Rhodotorula mucilaginosa and contents of carotenoids, crude fiber, crude protein, water, crude fat, ash, calcium, phosphorus, and amino acids in fermentation product were determined to evaluate the effects of the optimized fermentation process on the nutritional values of fermentation product. 【Result】 The results showed that there was a positive correlation between maize starch content in substrate and carotenoid content in fermentation product (r=0.344, P=0.040) or between rice bran content in fermentation substrate and carotenoid content in fermentation product (r=0.329, P=0.050). There was a significantly negative correlation between carotenoid yield and the content of wheat bran in solid-state fermentation substrate (r=-0.336, P=0.045). There was a positive correlation between the number of live bacteria of Rhodotorula mucilaginosa in fermentation product and the content of soybean meal in fermentation substrate (r=0.510, P=0.001). Inoculum, fermentation temperature, pH, and moisture had extremely significant impacts on the number of Rhodotorula mucilaginosa (P<0.01), thereinto, fermentation temperature had the greatest effect on the number of Rhodotorula mucilaginosa, followed by moisture, inoculum, and pH. Fermentation time, fermentation temperature, and pH had extremely significant influences on the carotenoid content in the fermentention product (P<0.01), and fermentation temperature had the greatest influence on the carotenoid content in the fermented product, followed by pH and fermentation time. After the optimization of the fermentation process, the carotenoid yield by Rhodotorula mucilaginosa TZR₂₀₁₄ was increased to 4 535 μg·kg^-1; the bacteria number was increased to 3.79×10⁹ CFU/kg; the contents of crude fiber, crude protein, ash, threonine, glutamate, and proline in fermentation product were significantly increased (P<0.05), meanwhile, the contents of histidine, water, and crude fat was significantly decreased (P<0.05). 【Conclusion】 The optimal ratio of solid-state fermentation substrate for Rhodotorula mucilaginosa was as followed: 52.5% wheat bran, 20.0% soybean meal, 3.0% maize flour, 14.0% rice bran, 10.0% maize syrup, 0.4% ammonium sulfate, 0.05% monopotassium phosphate, and 0.04% magnesium sulfate. The optimal fermentation conditions were as followed: inoculum 5.0%, fermentation time 72 h, fermentation temperature 28.0℃, pH 6.0, and moisture 60.0%. The results suggested that the optimized fermentation process of Rhodotorula mucilaginosa enhanced the yield of carotenoids and improved the nutritional value of fermentation product.

【Objective】 It has been shown that the entry of classical swine fever virus (CSFV) into host cells is mediated by clathrin-mediated endocytosis. However, the viral protein involved in entry stage remains to be elucidated. This study aimed to clarify the role of the E2 protein in the entry of CSFV. 【Method】 Lentivirus carrying the E2 gene were packaged by transient transfection of HEK-293T cells. A cell line stably expressing the E2 protein was established through transducing the suspension 293 cell with the lentiviruses. The expression of the recombinant E2 (rE2) protein was optimized to achieve higher production, and the rE2 protein was purified by affinity chromatography. The expression level and reactivity of the rE2 protein was identified by SDS-PAGE and Western blotting. The effects of the E2 protein on CSFV infection, attachment and internalization were determined by respective assays. Polyclonal anti-E2 antibodies were prepared by immunizing BALB/c mice with the rE2 protein, and its blocking rate was determined by blocking ELISA. Attachment and internalization assays were performed using the prepared polyclonal antibodies to demonstrate the role of the E2 protein in virus attachment and internalization. 【Result】 The cell line 293 was successfully transduced with the lentivirus vector. The SDS-PAGE produced the anticipated band size of rE2 no matter the sample was treated with the reducing agent or not. Western blotting results showed that the rE2 protein could be recognized by the anti-E2 monoclonal antibody WH303. The results indicated that suspension 293 cell line could stably express the rE2 protein. Under the optimized expression condition, the concentration of the rE2 protein in the supernatants of the established suspension 293 cell line was up to 5.84 μg·mL^-1. Soluble protein blocking assay results showed that the expressed rE2 protein exerted antiviral activity during the process of CSFV infection. CSFV infection were significantly inhibited by the rE2 protein treated in the entry step; Blocking ELISA and serum neutralization test showed that the anti-E2 polyclonal antibodies could neutralize CSFV infection; at the same time, attachment and internalization assays demonstrated that CSFV internalization could be inhibited by the rE2 protein and viral attachment was blocked by the polyclonal antibodies. 【Conclusion】 The E2 protein was involved in attachment and internalization of CSFV.

【Objective】 The aim of this study was to explore the effects of the total mixed ration (TMR) based on the whole-plant corn silage on the production performance and economic profit of fattening sheep of different varieties and therefore offer theoretical support to the application of the whole-plant corn silage and healthy sheep production. 【Method】 Nutritional composition and rumen degradation characteristics of the whole-plant corn before and after ensiling were evaluated by in Sacco method. Four varieties of 3-month-old healthy male lambs (breast-milk weaned) with similar body weight (27.6±1.7) kg, were selected. There were the following four treatments accordingly: Small-Tail Han (SH), “Dorper×Small-Tail Han” F₁ (DH), “Mongolia×Han” F₁ (MH) and “Dorper×Wadi” F₁ (DW). Each treatment had 30 lambs, which were divided into 3 replications. Forage to concentrate ratio of TMR is 25:75. There was an adaptation period of 10 days followed by an experimental period of 80 days, measuring the growth performance and slaughtering performance. 【Result】 Comparing to the whole-plant corn before ensiling, the silage did not have different content of crude protein (CP) (P>0.05) but owned greater DM, OM and rapidly degraded fraction (a) (P<0.01) and lower NDF, ADF and effective degradation rate (ED) (P<0.001). There was a tendency of higher DMI with hybrid sheep than with SH (0.05<P<0.1). The average daily gain (ADG), feed conversion ratio (FCR), carcass weight, neat weight, dressing percentage, neat percentage and neat percentage expressed in relation to carcass weight of DH and DW sheep were significantly higher than those of SH sheep (P<0.05). There was no significant difference in feed cost among all groups (P>0.05). The net meat gain, meat production efficiency and economic profit of DH and DW sheep were significantly higher than those of SH and MH sheep (P<0.01). 【Conclusion】 The whole-plant corn silage was suitable for use as the main feed source of TMR for fattening sheep, and all different breeds of sheep showed an expected production performance. The DH and DW hybrid sheep had a higher production performance and economic profit than that of SH sheep and MH hybrid sheep. However, there was no difference in production between SH and MH crossbred sheep. Therefore, DH and DW hybrid sheep were more suitable as fattening breeds in Huang-Huai-Hai farming area.

【Objective】 The objective of this study is to develop a real-time fluorescent quantitative PCR (RT-qPCR) method to detect the Tomato chlorosis virus (ToCV) and its concentration in plant and the vector Bemesia tabaci.【Method】 Firstly, the special primers ToCVqF/R were designed using Primer 3.0 for RT-qPCR based on the highly conserved region of the minor coat protein (CPm). The primers specificity was evaluated by Primer-BLAST. Secondly, the fragment was amplified using the primers ToCVqF/R by PCR within the ToCV-infected, Tomato yellow leaf curl virus (TYLCV)-infected, and Tomato spotted wilt virus (TSWV)-infected tomato samples, and cloned into pMD^TM 18-T Vector. The positive clone was selected and multiplied in LB liquid medium containing ampicillin. Furthermore, the recombinant plasmid was extracted from the clone and served as the ToCV standard. Then, the standard curve was generated for quantitative analysis using the ten-fold dilution of the recombinant plasmid. In addition, the detection sensitivity of RT-qPCR was also evaluated and compared to that of reverse transcription-polymerase chain reaction (RT-PCR). Finally, this method was used to detect and quantify ToCV in eight tomato samples with suspected ToCV infection and single B. tabaci after acquiring ToCV for 24 h, according to the amplification curves, melting curves and Ct values.【Result】 The purpose strips could be successfully amplified with the primers ToCVqF/R only in the ToCV-infected tomato sample and positive control, which indicated that the primers was highly specific. Additionally, the sequencing result of the fragment was in according with the target gene CPm. The ToCV standard curve showed that the Ct values gradually increased as the concentration of recombinant plasmid decreased. Among the concentration range of 2.7×10³-2.7×10⁹ copies/μL, the standard curve showed a good linear relationship between Ct values and plasmid concentration. The correlation coefficient of the standard curve was 0.9911, and the amplification efficiency was 100%. The Straight-line equation is y=-3.32×lgx+40.06 (y and x represent the Ct value and plasmid concentration, respectively). The sensitivity of RT-qPCR was 100 times higher than regular RT-PCR. The minimum detectable concentration of ToCV plasmid standard in RT-qPCR assay is 2.7×10³ copies/μL, while that in RT-PCR assay is 2.7×10⁵ copies/μL. This method could successfully detect the ToCV within tomato samples, and the result was consistent with RT-PCR assay. Six of eight tomato samples were infected by ToCV, the viral titers of which were 2.48×10⁵, 2.21×10⁵, 7.97×10⁴, 3.74×10⁷, 3.37×10⁷ and 2.78×10⁶ copies/μL, respectively. After 24 h feeding on ToCV infected tomato plants, 100% of the B. tabaci acquired this virus successfully, and the virus concentration in single whitefly ranged from 6.46×10² to 2.55×10⁴ copies/μL.【Conclusion】 The RT-qPCR method is applicable for accurate and sensitive detection of ToCV both in plants and vector insects, which will provide a technical support for the monitoring and early warning of this virus.