Loading...

Table of Content

    01 March 2018, Volume 51 Issue 5
    CROP GENETICS & BREEDING·GERMPLASM RESOURCES·MOLECULAR GENETICS
    Effects of Different Chemicals and Treatment Methods on Chromosome Doubling of Haploid Wheat Plants
    YIN MiQi, ZHANG ShuangXi, FAN ChunKun, WANG KunYang, WANG Jing, WANG Ke, DU LiPu, YE XingGuo
    Scientia Agricultura Sinica. 2018, 51(5):  811-820.  doi:10.3864/j.issn.0578-1752.2018.05.001
    Abstract ( 399 )   HTML ( 21 )   PDF (1974KB) ( 427 )   Save
    References | Related Articles | Metrics
    【Objective】 The treatment of tillering node with colchicine in a pump solution has long been widely used for chromosome doubling of haploid wheat plants before transplanting. However, this method has some disadvantages, for example, complicated manipulation and environmental or container pollution. Moreover, colchicine is some toxic, and large amount of application is not cost effective. The purposes of this study were to develop a simple, safe and efficient method for chromosome doubling of wheat haploid plants, and to evaluate a chemical that is suitable for the replacement of colchicine for chromosome doubling in wheat. 【Method】 The haploid wheat plants were obtained by anther culture for wheat line Fielder, and by crossing with the maize inbred line Zheng58 for wheat cultivars/lines Kenong199, Xinchun9, Chinese Spring and CB037 via chromosome elimination. Wheat line Chinese Spring was also crossed with rye line Gansu Heimai to produce wheat-rye double haploid plants. Chromosome doubling of different wheat haploid plants was conducted using the colchicine solutions at the concentrations of 0, 5, 10, and 20 mmol·L-1 through tiller node adding after transplanting, leaf painting after transplanting, and medium surface adding before transplanting. Additionally, the supplement of amiprophos-methyl, trifluralin, and propyzamide at the concentrations of 0, 30, 60 and 120 μmol·L-1 on medium surface adding was used to double chromosomes of the wheat haploid plants and the wheat-rye double haploid plants. The efficiency of chromosome doubling by different treatment methods was compared and the optimal concentrations of different chemicals were determined. 【Result】 Results indicated that the application of different concentrations of colchicine (0, 5, 10, and 20 mmol·L-1) by tiller node adding couldn’t be able to double the wheat haploid plants from the cross of wheat and maize, so it is not useful in chromosome doubling of wheat haploid plants. A doubling frequency of 7.7% was found when 10 mmol·L-1 colchicine was applied by leaf painting for the wheat haploid plants from maize pollen induction at jointing stage, but no haploid plant was doubled with other three concentrations of colchicine solutions, suggesting that this treatment method was also not useful for the doubling of the wheat haploid plants. The frequencies of chromosome doubling for the wheat haploid plants generated from anther culture treated with the four colchicine concentrations by medium surface adding were 26.7%, 42.9%, 73.3%, and 85.7%, respectively. It is demonstrated that the supplement of colchicine solution on medium surface adding resulted in the highest efficiency of chromosome doubling for the wheat haploid plants and the optimal concentration is at least 20 mmol·L-1. The frequency of chromosome doubling for the haploid plants generated from the cross of wheat and maize by medium surface adding of propyzamide at the concentrations of 0, 30, 60, and 20 μmol·L-1 was 0, 0-57.1%, 28.6%-75.0%, and 0-100%. However, the other two herbicides used by this method were not effective in chromosome doubling. The frequency of chromosome doubling by medium surface adding of 120 μmol·L-1 propyzamide for the wheat-rye double haploid plants was 9.0%. No seed was produced by the other three concentrations of propyzamide and the other three agents (amiprophos-methyl, trifluralin, and colchicine). 【Conclusion】 It is concluded that propyzamide at the concentration of 60-120 μmol·L-1 produced promising results of chromosome doubling for the wheat haploid plants. The medium surface adding of colchicine and propyzamide at appropriate concentrations is effective and easily adopted to double chromosomes of wheat haploid plants.
    Genome-Wide Association Studies of Plant Type Traits in Maize
    LIU Kun, ZHANG XueHai, SUN GaoYang, YAN PengShuai, GUO HaiPing, CHEN SiYuan, XUE YaDong, GUO ZhanYong, XIE HuiLing, TANG JiHua, LI WeiHua
    Scientia Agricultura Sinica. 2018, 51(5):  821-834.  doi:10.3864/j.issn.0578-1752.2018.05.002
    Abstract ( 569 )   HTML ( 17 )   PDF (2749KB) ( 1105 )   Save
    References | Related Articles | Metrics
    【Objective】 Plant morphological traits are the basis of ideotype-based maize breeding which are closely related to photosynthetic efficiency, lodging resistance and grain yields. Genome-wide association studies (GWAS) of 558 629 SNPs with genome-wide coverage was used to elucidate the genetic basis of six plant morphological traits, including total number of leaves (LN), leaf number above ear (LNAN), the ratio of LNAN to LN (LNAN/LN), plantheight (PH), earheight (EH) and the ratio of EH to PH (EH/PH), which could provide theoretical basis in enhancing ideotype-based maize breeding and facilitating the genetic improvement of new maize varieties with high plant density and lodging resistance. 【Method】 In this study, a representative panel of 284 inbred lines planted in Zhengzhou and Xunxian, including temperate, subtropical and tropical materials, were used for association mapping.【Result】 All traits measured in the two locations exhibited an approximately normal distribution. Highly positive or negative correlations between paired traits were observed. Variance analysis of these traits indicated that significant variations were observed across environment, genotype and the genotype × environment interaction. When test with the optimal GWAS model, we found that Q model showed high type I errors (false positive), while Q+K model were too strict in reducing false positive. K model is the best in reducing false positive. Totally, 56 significant SNP-trait associations involving in 17 loci were identified for five traits (P≤3.99E-6), each locus can explain phenotypic variation ranging from 7.97% to 10.56%. Moreover, four loci were detected in both environments, indicating that these 4 loci were less affected by environment effects and could be stable in different environments. All potential candidate genes and their annotations within 100 kb (50 kb upstream and downstream of the lead SNP) of the loci were identified, in total, 80 candidate genes were found, including 42 genes that have functional annotation. For example,the gene GRMZM2G161293 encoding a protein that has acetylgluco-saminyl transferase is associated with plant height and ear height. It catalyzes the transfer of the amino group from N-acetyl glucosamine to glucose, which may improve yield by influencing the content of soluble sugars in maize kernels.【Conclusion】 The results indicated that K model having the best result in reducing the type I errors (false positive). Based on K model, a total of 17 loci associated with plant morphological traits were identified.
    Characteristics and Comprehensive Assessment of Principal Nutritional Components in Adlay Landraces
    LI XiangDong, PAN Hong, LU XiuJuan, WEI XinYuan, LU Ping, SHI Ming, QIN LiKang
    Scientia Agricultura Sinica. 2018, 51(5):  835-842.  doi:10.3864/j.issn.0578-1752.2018.05.003
    Abstract ( 322 )   HTML ( 8 )   PDF (743KB) ( 618 )   Save
    References | Related Articles | Metrics
    【Objective】Nutritional quality analysis and evaluation is a significant procedure of adlay breeding and comprehensive utilization. In order to providing the base materials for quality improvement breeding, methods for quality evaluation, which can be a essential process in product chain, would be built, the superior adlay landraces were discovered and selected as well.【Method】The indices of nutritional quality were determined and a comprehensive evaluation on nutritional quality of Job’s Tears was obtained with correlation analysis, subordinate function and factor analysis in all 86 landraces.【Result】The results showed that there were differences and rich diversities in contents of starch, fat, protein and amino acid among all of the 86 adlay landraces, with a variable coefficient rate ranged from 5.01%-116.90%. Average contents of 8 essential amino-acid components ranged from 0.33%-2.47%, which leucine possessing a maximum content and lysine was first restricted one. There were 35 waxy accessions with a percentage of 40.70%, 34 accessions with a fat content more than 8%, and 8 accessions with a protein more≥20%, respectively. ‘Changliyimi’ and ‘Changliheichuangu’ accessions had a relatively higher total amino-acid contents as well. Total starch related positively to amylose and negatively related to amylopectin at significant level, while amylopectin significantly related to fat positively, fat positively related to protein, total amino-acid and serine contents. Most of 8 essential amino-acids also related to each other at significant levels, which revealed by correlation analysis. Four principal factors were extracted from the 14 nutritional factors, which contributed 48.333%, 16.571%, 16.011% and 6.146% to all date information, respectively, with a cumulative percentage of 87.061%, while the protein, total amino-acid and five essential amino-acids decided the first principal factor and methionine, lysine, serine decided the second principal factor; the second principal factor was decided by amylase, amylopectin and fat, while total starch decided the fourth principal factor. According to weight index and subordinate function value of five principal factors, the comprehensive evaluation of nutritional quality scores were calculated for ranking. The results also showed that factor analysis is a good statistical method for evaluating nutritional quality by simplifying the some correlated variables to minority ones.【Conclusion】It was concluded that the tested adlay landraces had a various diversity, and was full of essential amino acids; the type of waxy in endosperm, higher protein and higher fat were also discovered. Most of indices were related to each other revealed by correlation analysis. Several landraces with a higher score were selected, which were ‘Changliyimi’, ‘Changliheichuangu’, ‘Yixiannongjiazhong’, ‘Taiwahuake’, ‘Guizhouyiyi’, ‘Anguowugu’, ‘Liaoningbendiyiyi’, ‘Chengdeyimi’, ‘Panxianwugu’ and ‘Huajialiugu’, providing fundamental materials for quality improvement and breeding process. Most of indices were related to each other revealed by correlation analysis.
    TILLAGE & CULTIVATION·PHYSIOLOGY & BIOCHEMISTRY·AGRICULTURE INFORMATION TECHNOLOGY
    Effect of No-Tillage on Maize Yield in Northern Region of China—A Meta-analysis
    YIN MinHua, LI YuanNong, CHEN PengPeng, XU LuQuan, SHEN ShengLong, WANG XingYao
    Scientia Agricultura Sinica. 2018, 51(5):  843-854.  doi:10.3864/j.issn.0578-1752.2018.05.004
    Abstract ( 360 )   HTML ( 9 )   PDF (849KB) ( 424 )   Save
    References | Related Articles | Metrics
    【Objective】This study was conducted to reveal the influence mechanism and comprehensive effect of no-tillage on maize yield in Northern China. This study will provide valuable information for the application of no-tillage technology. 【Method】The maize in the northern region of China was taken as the research object. A total of 68 papers (including 82 available comparisons) were selected from published papers at home and abroad before May in 2017. Key information, containing experimental site, annual average precipitation, annual average temperature, cropping system, tillage pattern, experimental duration, experimental year, maize yield, standard deviation of maize yield, and replicate, were abstracted from each study. The site was divided into northwest region of China, northern region of China, and northeast region of China. The annual precipitation and average annual temperature was classified as <500 mm and ≥500 mm, <10℃ and ≥10℃, respectively. The experimental duration was split into four classes of 1-2 a, 3-5 a, 6-9 a, and ≥10 a. The tillage pattern was divided into flat planting and ridge planting. The cropping system was classified as continuous cropping and rotation cropping. Straw returning or not was also carried out. The analysis steps consist of heterogeneity test, comprehensive effect size calculation, publication bias test, sensitivity analysis, cumulative meta-analysis, and influence factor analysis. 【ResultThere were no publication bias and extreme values among the obtained data. No-tillage could significantly increase maize yield compared with traditional tillage. The average yield increasing rate was 3.1% with a confidence interval of 0.7%-5.5%. The cumulative yield increasing rate under no-tillage was unstable before 2000 with average values of -0.7%-6.6%. The differences in cumulative yield increasing rates between no-tillage and traditional tillage, however, gradually changed from non-significant to significant after 2000. No-tillage showed a significant yield increasing rate (average value of 5.3% and confidence interval of 1.5%-9.2%) in northeastern region of China, while the yield effect was not significant in northern region of China and northwestern region of China (average value of -2.6%-6.4% and -1.0%-6.4%, respectively). Maize yield under no-tillage significantly increased in the regions where annual precipitation was less than 500 mm and average annual temperature was lower than 10, and in the conditions of rotation tillage and straw returning. The average yield increasing rate was 5.4% (confidence interval of 1.7%-9.1%), 3.8% (confidence interval of 0.8%-6.7%), 4.4% (confidence interval of 1.3%-7.5%), and 3.3% (confidence interval of 0.8%-5.8%), respectively. The yield effect of no-tillage between ridge planting and flat planting was not significantly different. After 2010, the yield effect of no-tillage was significant (average value of 6.1%), and the amplitude was small (confidence interval of 2.5%-9.7%). The average yield increasing rate increased first and then decreased with the extension of the no-tillage duration. The yield effect was significant and reached the maximum (average value of 3.8% and confidence interval of 1.6%-6.0%) when no-tillage lasted for 3-5 years. 【Conclusion】It helps to improve the effect of no-tillage in northeastern region of China and in regions where annual precipitation is less and annual average temperature is lower. The reasonable no-tillage durations are 3-5 years.  
    Remote Sensing Inversion of Leaf Area Index of Winter Wheat Based on Random Forest Algorithm
    ZHANG ChunLan, YANG GuiJun, LI HeLi, TANG FuQuan, LIU Chang, ZHANG LiYan
    Scientia Agricultura Sinica. 2018, 51(5):  855-867.  doi:10.3864/j.issn.0578-1752.2018.05.005
    Abstract ( 437 )   HTML ( 11 )   PDF (1502KB) ( 824 )   Save
    References | Related Articles | Metrics
    【Objective】The objective of this study is to quickly and precisely monitor the growth of winter wheat by inversion of leaf area index (LAI) using random forest algorithm. Thus it could provide a guideline in crop management and mitigation, high and stable yield, agricultural insurance claims, etc.【Method】In this study, field data of canopy reflectance and LAI of winter wheat of four critical growth stages (i.e., jointing period, flag leaf period, flowering period and filling period), were collected under different treatments. The correlation coefficient (r) analysis and the importance analysis of out-of-bag data (OOB) were combined with the random forest algorithm (RF) to determine the more suitable spectral indices and the optimal number of variables for inputs, and then two LAI inversion models (|r| -RF, OOB-RF) were constructed and validated with independent data-sets. Further, the proposed LAI inversion model was applied to the (unmanned aerial vehicle) UAV remote sensing platform to evaluate its performance and reliability for monitoring LAI of winter wheat.【Result】The results showed that the best accuracy of |r|-RF and OOB-RF inversion models was achieved when the top five spectral indices in the correlation and the top two spectral indices in the importance were used as input variables, respectively. The coefficients of determination (R2) of |r|-RF and OOB-RF models during LAI validation were 0.805 and 0.899, and the root mean square errors (RMSE) were 0.431 and 0.307, respectively, which indicated that both |r|-RF and OOB-RF models could well estimate LAI of winter wheat, while the accuracy of the latter was much higher. The retrieved LAI from the UAV hyperspectral images using the OOB-RF model was in well agreement with the ground measured values, with R2=0.761, RMSE=0.320, and the range of estimated values (i.e., 1.02-6.41) also consistent with that actually measured (i.e., 1.29-6.81).【Conclusion】The OOB-RF model constructed in this study not only has high retrieval accuracy, but also can be used to extract high-precision winter wheat LAI information from UAV hyperspectral remote sensing platform.
    Effects of Drought Stress on Root and Physiological Responses of Different Drought-Tolerant Alfalfa Varieties
    ZHANG CuiMei, SHI ShangLi, WU Fang
    Scientia Agricultura Sinica. 2018, 51(5):  868-882.  doi:10.3864/j.issn.0578-1752.2018.05.006
    Abstract ( 533 )   HTML ( 44 )   PDF (470KB) ( 696 )   Save
    References | Related Articles | Metrics
    【Objective】This study aimed to understand the differential growth and physiological response in roots of different drought-tolerant alfalfa varieties to drought stress, and to provide theoretical basis for further clarifying the molecular mechanism of alfalfa against drought and for improving drought tolerance and water use efficiency in alfalfa.【Method】In a sand culture experiment, three different drought-tolerant alfalfa varieties, including Medicago sativa L. cv. Longzhong (strong drought-tolerant), Medicago sativa L. cv. Longdong (moderate drought-tolerant), and Medicago sativa L. cv. Gannong No.3 (drought-susceptible), were treated with drought stress induced by polyethylene glycol-6000 (PEG-6000) solutions of different osmotic potentials (0.0, -0.4, -0.8, -1.2, -1.6 and -2.0 MPa). The root growth characters of total root length, total root surface area, average root diameter, root volume, root tip number and root dry weight, root activity, the contents of free proline, soluble protein, and soluble sugar, relative permeability of plasma (RPP), the levels of malondialdehyde (MDA) and reactive oxygen species (ROS), the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), and reduced ascobate (AsA) and reduced glutathione (GSH) contents were measured at seedling stage. Moreover, stepwise regression analysis was used to establish the optimal regression equation that could select the influential indices for drought-tolerance of the alfalfa varieties under different drought stress levels.【Result】Drought stress has an obvious effect on growth and physiological traits of the alfalfa varieties. With increasing drought stress, the free proline contents, the levels of MDA, RPP and ROS (H2O2, OH· and O2•-), and CAT activity in roots of three alfalfa varieties were significantly increased, while root dry weight, root activity, and the contents of soluble sugar and GSH were firstly increased and then decreased. Additionally, as the osmotic potentials of solutions decreased, average root diameter, root volume, root tip number, POD and SOD activities of Longzhong increased first and then decreased, whereas the above first four indicators and total root surface area of Longdong and Gannong No.3 decreased continuously. Moreover, with the increase of stress, the AsA content of Longzhong continuously increased but that of the other two varieties increased first and then decreased. Overall, total root length, total root surface area and root dry weight in roots of Longzhong were significantly greater than those of Longdong and Gannong No.3, while the H2O2 and OH· levels in roots of Longzhong were significantly lower than those of Gannong No.3. The contents of soluble protein, soluble sugar and MDA in roots of Longzhong and Longdong were obviously lower than those of Gannong No.3. Under the drought stress from -1.2 to -2.0 MPa, the H2O2 and OH· contents in roots of Longzhong were significantly lower than those of Longdong. Under -2.0 MPa, the AsA and GSH contents and POD activity in roots of Longzhong were significantly higher than those of Gannong No.3. The result of stepwise regression analysis showed that root activity, root volume, total root length, MDA and AsA were the most influential indices for drought-tolerance of Longzhong; Root tip number, average root diameter, total root surface area, root dry weight, O2•-, GSH and CAT were the most influential indices for drought-tolerance of Longdong; and root activity, root tip number, free proline, soluble sugar, MDA, RPP and GSH were the most influential indices for drought-tolerance of Gannong No.3.【Conclusion】The alfalfa varieties with different drought-tolerance exhibit common and divergent responses to drought stress at the morphological and physiological levels. Under light and mild drought stress conditions (osmotic potentials decreased from 0 MPa to -1.2 MPa), drought-tolerant alfalfa varieties mainly adapted to drought by increasing the root length, root volume and root tip number and reducing the degree of membrane lipid peroxidation, while drought-susceptible alfalfa varieties adapted to drought by changing cell membrane stability, root activity and osmotic adjustment. Under severe drought stress (osmotic potentials declined from -1.2 MPa to -2.0 MPa), the alteration of root growth and activation of antioxidant system were common response mechanisms of tested alfalfa varieties. Furthermore, strong drought-tolerant alfalfa variety increased total root length and AsA content against drought stress, while moderate drought-tolerant and drought-susceptible alfalfa varieties increased root tip number and GSH content in response to drought stress.
    PLANT PROTECTION
    Antagonism of Bacillus methylotrophicus Strain BH21 to Botrytis cinerea
    WEI XinYan, HUANG YuanYuan, HUANG YaLi, DU KeJiu
    Scientia Agricultura Sinica. 2018, 51(5):  883-892.  doi:10.3864/j.issn.0578-1752.2018.05.007
    Abstract ( 275 )   HTML ( 9 )   PDF (1072KB) ( 770 )   Save
    References | Related Articles | Metrics
    【Objective】Bacillusmethylotrophicusstrain BH21 is a marine derived bacterium that has a good antagonistic effect on Botrytis cinerea. The objective of this study is to identify the lipopeptide synthesis genes of the strain BH21 and investigate the antagonism of the crude extracts of lipopeptide to B. cinerea, and to provide a scientific basis for the prevention and control of B. cinerea. 【Method】 To determine the mechanisms of the antagonistic strain, PCR was used to screen strain BH21 for genes involved in biosynthesis of antimicrobial lipopeptide. Crude lipopeptide was extracted from the culture broth by hydrochloric acid precipitation and methanol extraction. surface activity of the crude lipopeptide was determined by oil spreading method. The inhibition ability of the crude lipopeptide on mycelial growth of B. cinerea was investigated by mycelial growth rate method and EC50 was calculated. The crude lipopeptide was separated by liquid chromatography (HPLC) and the inhibition ability of each component to B. cinerea was detected by the mycelium growth rate method. Reversed phase high performance liquid chromatography (RP-HPLC) was used to analyze the types of the main antifungal components. the effect of the crude lipopeptide on the control of B. cinerea in grape was detected by tissue inoculation in vitro. 【Result】 A total of 11 pairs of specific primers were used for genomic amplification of strain BH21, and 7 gene fragments of the size expected to be correlated with biocontrol activities were efficiently amplified. after amplification, sequencing and BLAST analysis, the results showed that the similarity between the amplified products and the related lipopeptide genes was 96%-99%, the similarity between the protein produced by the nucleic acid fragment and the lipopeptide synthesized protein of the related strain was 96%-100%, which showed that the genome of strain BH21 contained ituA, bamD, ituC, ituD, fenD, srfAB and yndJ genes and the strain had the ability to synthesize antimicrobial lipopeptide such as surfactins, iturins and fengycins. Antifungal lipopeptide produced by BH21 was extracted by hydrochloric acid precipitation and methanol extraction, and the yield was 428 mg·L-1. The results of the oil spreading test showed that the crude lipopeptide had surface activity. The crude lipopeptide significantly inhibited mycelial growth of B. cinerea when the concentration was 440 μg·mL-1, the relative inhibition rate of mycelial growth of B. cinerea was 82.8%, and the effective medium concentration EC50 was 144.39 μg·mL-1. Six fractions were collected with elution time through HPLC, only BH21-2 and BH21-3 inhibited the growth of B. cinerea. RP-HPLC chromatogram analysis showed that the components BH21-2 and BH21-3 belong to the fengycin family. Grape leaf in vitro test results showed that when the concentration of crude lipopeptide was 440 μg·mL-1,the control effect againstgrape gray leaf spot was 100%, while the concentration was 220 μg·mL-1, the relative inhibitory rate of grape leaf lesion was 94.4%.【Conclusion】 The strain BH21 has the genes for synthesizing antimicrobial lipopeptide such as surfactins, iturins and fengycins, and the lipopeptide extracted from this strain has strong antagonism to B. cinerea, so it has potential application in the biological control of B. cinerea.
    Identification and Function of the OBP13 Protein from the Leafminer (Liriomyza sativae)
    CHEN DongKai, ZHANG LinYa, XING ZhenLong, LEI ZhongRen
    Scientia Agricultura Sinica. 2018, 51(5):  893-904.  doi:10.3864/j.issn.0578-1752.2018.05.008
    Abstract ( 262 )   HTML ( 12 )   PDF (2375KB) ( 325 )   Save
    References | Related Articles | Metrics
    【Objective】The objective of this study is to clone and clarity odorant binding protein gene in the leafminer (Liriomyza sativae), analyze the sequence properties, gene expression, phylogeny and protein function, which would provide a basis for further study of the olfactory mechanism.【Method】The whole coding region of OBP gene from L. sativae was cloned by PCR strategy. Nucleotide sequence was analyzed using DNAMAN and homology comparison was analyzed using BLAST. An evolutionary tree was constructed by MEGA 6.0 to analyze phylogeny. Expression situation of LsatOBP13 in different tissues was assayed by the real-time quantitative PCR. Prokaryotic expression vector was constructed and then the recombinant protein was expressed and purified. The excitation wavelength of the fluorescence spectrophotometer was 337 nm and the 1-NPN was used as fluorescent probe to study the binding properties of OBP13 with 25 different odor ligands. The distribution of the LsatOBP13 was located by the indirect immuno-fluorescent staining and specific polyclonal antibody which was already prepared. The antenna of L.sativae was embedded, sliced up and observed under laser scanning confocal microscope to study the subcellular distribution of OBP13.【Result】An OBP gene in L.sativae was obtained and named as LsatOBP13. The accession number in GenBank ID is KT250751. The whole length of LsatOBP13 coding region is 462 bp that encodes a putative protein of 153 amino acids with a molecular mass of 17.80 kD and an isoelectric point of 5.75, and deduced amino acid sequence possesses a putative signal peptide of 17 amino acid residues at the N terminus. There are four conservative cysteine sites in the protein sequence, so that the LsatOBP13 is a Minus-C OBP. Phylogenetic analysis showed that the OBP13 and CcapOBP99a-like were clustered into one branch and had a high homology. According to the expression level in different tissues, the expression level in the antenna was much higher than that in other tissues. The recombinant expression vector was successfully constructed and the recombinant protein of high purity was obtained. After testing combining capacity of 25 odor ligands, it was found that LsatOBP13 had a good combining capacity with trans-2-hexenal, linalool, 1-octen-3-ol, α-ionone, benzothiazole and β-ionone, and the dissociation constants were 12.592, 10.995, 11.165, 11.224, 10.336, 9.218 μmol·L-1, respectively. In these 6 kinds of odors, the affinity of β-ionone was the strongest. By immunofluorescence localization, it was found that it was mainly located in trichoid sensilla and basiconic sensilla on the crosscut flagellum section, and also in the olfactory pit and the joint of arista and funicular section.【Conclusion】The LsatOBP13 is a Minus-C OBP which belongs to the atypical OBPs. Expression situation, odorant binding characteristic and immunofluorescence localization showed that OBP13 existed mainly in the antenna of L. sativae and involved in the recognition process of odors in green leafed plants. It is presumed that it plays a role in olfactory recognition and host plant location of L.sativae.
    In Vitro Expression of TcGSTM7 of Tetranychus cinnabarinus and Its Function
    SHEN GuangMao, LI Heng, LIANG JinHui, HE Lin
    Scientia Agricultura Sinica. 2018, 51(5):  905-913.  doi:10.3864/j.issn.0578-1752.2018.05.009
    Abstract ( 256 )   HTML ( 8 )   PDF (1652KB) ( 333 )   Save
    References | Related Articles | Metrics
    【Objective】 Tetranychus cinnabarinus is an important pest mite in agriculture. Resistance of this pest mite to various pesticides has developed quickly because of long-term chemical control, thus, it is of great significance to clarify the detoxification mechanism of T. cinnabarinus in order to carry out effective resistance management. Glutathione S-transferase (GST) is one of the major detoxification enzymes in Arthropods. In previous research, a highly expressed GST gene TcGSTM7 from T. cinnabarinus was identified, and the expression of this gene is inducible by pesticide. In this case, the objective of this study is to construct the recombinant protein of TcGSTM7 with prokaryotic expression system, analyze interaction between recombinant protein and pesticides (fenpropathrin and cyflumetofen), and test the pesticide susceptibility change of T. cinnabarinus after decreasing the expression of TcGSTM7 through RNAi.【Method】The sequence characteristics of TcGSTM7proteinwere annotated by BLAST in NCBI database. The structural domain, binding site, and active site were presented in a three-dimensional structure model, which was predicted by SWISS MODEL. TcGSTM7 was expressed by prokaryotic expression in Escherichia coli. GST activity of recombinant protein was tested with specific substrate, and its interaction with fenpropathrin and cyflumetofen was analyzed through activity inhibition test. Then, specific dsRNA was synthetized according to the sequence information of TcGSTM7. T. cinnabarinus was feed on the dsRNA through leaf disc method. Gene expression change of TcGSTM7 was detected by qPCR, then, susceptibility change of T. cinnabarinus to fenpropathrin and cyflumetofen was analyzed by bioassay. 【Result】Amino acid sequence analysis ofTcGSTM7 showed that the N-terminal domain contained a thioredoxin-like domain, which is a specific feature of Mu class GST. In addition, GSH binding site (G-site) was also located in the N-terminal domain. The C-terminal domain contained an alpha helical domain, and the substrate binding pocket (H-site) was included. This protein consisted of nine α-helices and four β-strands and contained the typical βαβαββα motif of the thioredoxin fold. Based on the three-dimensional structure prediction, recombinant protein of TcGSTM7 was constructed through prokaryotic expression. Molecular weight of this protein was 26 kD, which was the same as prediction. Its GST specific activity was 673.26 nmol·min-1·mg-1, and kinetic parameters were calculated as 0.71 mmol·L-1 for Km and 109.54 nmol·min-1·mg-1 for Vmax. Analysis of interaction between pesticides and the recombined protein showed that both fenpropathrin and cyflumetofen could inhibit the activity of TcGSTM7. IC50 was 0.038 mmol·L-1 for fenpropathrin, and 0.2 mmol·L-1 for cyflumetofen. Then, dsRNA was feed to T. cinnabarinus by leaf disc feeding method. qPCR data showed the expression of TcGSTM7 was significantly decreased by 52.88%, and bioassay was carried out to test susceptibility of the mites to these two pesticides. Results showed that susceptibility of T. cinnabarinus to fenpropathrin significantly increased by 9.0% and 12.3% at LC30 and LC50, and to cyflumetofen, it also significantly increased by 12.9% and 11.0% at LC30 and LC50 (P<0.05).【Conclusion】The expression of TcGSTM7 could affect the susceptibility of T. cinnabarinus to fenpropathrin and cyflumetofen, and the interaction between recombinant protein of TcGSTM7 and these two pesticides was identified. These data indicate that TcGSTM7 is important for T. cinnabarinus during its metabolism process of fenpropathrin and cyflumetofen.
    SOIL & FERTILIZER·WATER-SAVING IRRIGATION·AGROECOLOGY & ENVIRONMENT
    Response and Driving Factors of Bacterial and Fungal Community to Long-Term Fertilization in Black Soil
    WANG HuiYing, XU MingGang, ZHOU BaoKu, MA Xiang, DUAN YingHua
    Scientia Agricultura Sinica. 2018, 51(5):  914-925.  doi:10.3864/j.issn.0578-1752.2018.05.010
    Abstract ( 367 )   HTML ( 14 )   PDF (431KB) ( 825 )   Save
    References | Related Articles | Metrics
    【Objective】This study was conducted to explore the bacterial and fungal community responses to long-term chemical fertilizer and manure application, and thus to clarify the biological mechanism of fertilization on soil fertility in black soils. It aims to provide a theoretical support for rational application of fertilizer and black soil fertility improvement. 【Method】The study was conducted on the long-term fertilization (35 years) experiment at Harbin, China. Soil samples were collected from the following four treatments: control, non-fertilization (CK), chemical nitrogen fertilizer (N), manure only (M) and M plus N (MN). Miseq pro-sequencing and qPCR technology were used to find out the difference between bacterial and fungal communities. In combination with soil properties, we analyzed the driving factors for bacterial and fungal community by multivariate statistical analysis. 【Result】Compared with CK, N treatment significantly decreased bacterial diversity and fungal diversity by 13.2%-48.5% and 4.6%-80.3%, respectively, while fungal abundance was increased by 24 times. Applied manure to N fertilization enhanced bacterial abundance and bacterial diversity by 2 times and 7.7%-46.6%, respectively. However, fungal quantity was declined by 14.2% and fungal diversity was increased by 62%-237%, comparing MN with N only fertilizer. In comparison with CK, the abundance of Acidobacteria_Gp1, Gp3 and α-Proteobacteria (bacterial classes) were significantly increased, and Agaricomycetes (fungal class) even was enhanced by 41 times with the addition of N. Compared with N treatment, the bacterial abundance kept constant for MN treatment, while the abundance of α-Proteobacteria, Acidobacteria_Gp1 and Gp3 were decreased, and Acidobacteria_Gp4, GP6 and Plancomycetes were increased for M treatment. Bacterial community structure for MN and N treatments appeared similar, which were significantly different from CK and M treatments. Fungal community structure for CK, M and MN treatments were similar and significantly different from N treatment. Soil pH (6.07) and available potassium (125.5 g·kg-1) were the principal factors for the difference of bacterial community and fungal community, respectively. Soil organic matter explained both bacterial and fungal community structure alternations while the criteria was different as 28.4 g·kg-1 for bacteria and 30.8 g·kg-1 for fungi. 【Conclusion】Therefore, our results indicate that bacteria was sensitive to the manure, and fungi was sensitive to N fertilizer application. Long term N application stimulated the growth of acidophilic microbe, while addition of manure to N enhanced microbial diversity and promoted the growth of beneficial microorganism. Soil pH and available potassium were the principal factors driving bacterial and fungal community structure, respectively. Further detailed study is required on this aspect for the improvement of black soil quality.
    Environment Risk for Application of Flue Gas Desulfurization Gypsum in Soils in China
    WANG XiaoBin, YAN Xiang, LI XiuYing, CAI DianXiong, LEI Mei
    Scientia Agricultura Sinica. 2018, 51(5):  926-939.  doi:10.3864/j.issn.0578-1752.2018.05.011
    Abstract ( 610 )   HTML ( 8 )   PDF (495KB) ( 609 )   Save
    References | Related Articles | Metrics
    Utilization of flue gas desulfurization (FGD) gypsum in China to improve alkaline soils started in the late 1990s. The FGD gypsum is a kind of desulfurized waste residue from power plant. It is an industrial by-product gypsum obtained by desulfurization and purification of flue gas produced by sulfur bearing fuel (mainly coal). With the increasing of installation of flue gas pollution control system, such as dust removal, desulfurization and denitrification in coal-fired power plants in China, more and more desulfurization by-product gypsum will be produced while reducing SO2 emission and other harmful gases in the process of coal combustion. The utilization of FGD gypsum has attracted more attention for solving the problem with increased disposal of desulfurization residues in power plants. Because the nature of FGD gypsum is similar to that of natural gypsum, some researchers have tried to use it instead of natural gypsum in the improvement of saline alkali land. However, since some enterprises introduced flue gas purification technology and synergistic mercury removal process, several hazardous pollutants in coal would inevitably transfer into FGD by-products (FGD gypsum and fly-ash). The process of FGD and synergistic mercury removal causes the enrichment of several hazardous pollutants in FGD gypsum (mainly Hg, F, Cl, and Se), and in FGD fly-ash (mainly As, Cd, Cr, Cu, Ni, Pb, and Zn). Research results indicated that the enrichment of hazardous pollutants could result in high levels of hazardous pollutants (especially Hg, Se, F and Cl) in some FGD gypsum in China, inordinately beyond the limits of Environmental Quality Standards for Soils and the limits of Environmental Quality Standards for Ground Water. In order to ensure soil health, food safety, and environmental quality, it was suggested that those FGD by-products without any harmless treatment of pollutants should not be allowed to use as for soil remediation or conditioning directly into the farmlands by solid waste disposal methods; especially material source and technology of desulfurization, application rate in farmland and long-term environmental safety risk should be concerted, to prevent hazardous pollutants from entering food chain and harming to human health.
    HORTICULTURE
    Effect of Planting Row Spacing and Irrigation Amount on Comprehensive Quality of Short-Season Cultivation Tomato in Solar Greenhouse in Northwest China
    WU XuanYi, CAO HongXia, WANG HuBing, HAO ShuXue
    Scientia Agricultura Sinica. 2018, 51(5):  940-951.  doi:10.3864/j.issn.0578-1752.2018.05.012
    Abstract ( 289 )   HTML ( 6 )   PDF (1878KB) ( 435 )   Save
    References | Related Articles | Metrics
    【Objective】The objectives of the study were to investigate the effect of planting row spacing and irrigation amount on the tomato quality cultivated in solar greenhouse in Northwest China, to obtain the best combination of irrigation amount and planting row spacing for the best comprehensive quality, so as to provide a scientific basis and technical guidance for irrigation and cultivation management of greenhouse tomato in the region.【Method】The experiment was conducted in solar greenhouse at the Green Lily fruit and vegetable cooperatives in Yangling Agricultural Hi-tech Industries Demonstration Zone in Shaanxi province. The cultivated varieties of tomato in the experiment was HL2109.The treatments comprised three planting row spacing (L1 (60 cm), L2 (45 cm), L3 (30 cm)), and based on the cumulative evaporation from a 20 cm diameter pan between two irrigations (E), 0.6 E, 0.8 E, 1.0 E, 1.2 E were set as four different levels of irrigation amount, when the cumulative evaporation reached (20±3) mm irrigation will be conduct. The treatments were replicated three times in randomized complete block designs. The comprehensive quality of tomato was evaluated by improved fuzzy grey relational method and CRITIC method, respectively. The two evaluation results were compared and multivariate regression analysis was used to find the best combination of irrigation amount and planting row spacing when the best comprehensive quality was obtained.【Result】Tomato quality was affected by both planting row spacing and irrigation amount, and showed a very significant interaction on soluble solids, Vc and lycopene, but the appearance fruit quality indicators of tomato do not exist irrigation amount and planting line spacing between the interaction. Excessive irrigation will reduce the exterior quality of tomato, and reduce the soluble solids, Vc and lycopene content. The results of the improved fuzzy grey relational method and CRITIC method have good agreement with the results of tomato comprehensive quality evaluation, that the L2-0.8E treatment had the best comprehensive quality of tomato, and the L1-1.2E treatment was the worst; the comprehensive quality of tomato followed a downward quadratic parabola shape with the increase of irrigation amount and planting row spacing. Although the proportion of weights for single tomato quality indicators have a little difference between two tested seasons, but the weights of lycopene, Vc and sugar acid ratio are always the first three. 【Conclusion】 When the ridge distance is 80 cm, planting spacing is 35 cm, the planting row distance selected 37-47 cm, the irrigation quantity is set to 0.8E-1.0E would be the appropriate combination of irrigation amount and planting row spacing for best comprehensive quality of greenhouse tomato in Northwest China.
    Effect of Root-Applied Melatonin on Endogenous Melatonin and Chlorophyll Fluorescence Characteristics in Grapevine Under NaCl Stress
    BIAN FengE, XIAO QiuHong, HAO GuiMei, SUN YongJiang, LU WenLi, DU YuanPeng, ZHAI Heng
    Scientia Agricultura Sinica. 2018, 51(5):  952-963.  doi:10.3864/j.issn.0578-1752.2018.05.013
    Abstract ( 309 )   HTML ( 7 )   PDF (860KB) ( 643 )   Save
    References | Related Articles | Metrics
    【Objective】 The content of the endogenous MT, the key metabolites, and the effect of photoinhibition on the leaf were studied in grapevine under NaCl stress, and the results will provide a reference for the application of MT in the future.【Method】One-year old potted ‘Vidal Blanc’ grapevines (Vitis vinifera cv. Vidal Blanc) were used as materials. The grapevines were irrigated with NaCl (100 nmol·L-1 ) and NaCl+MT (100 nmol·L-1), and then the content and distribution of the endogenous MT, MT precursors serotonin (5-hydroxytryptamine, 5-HT), and then the main metabolites of melatonin 2-hydroxymelatonin (2-OHMel) in different organs of different treatment plants, and the chlorophyll fluorescence characteristics in leaves and the metabolism of endogenous MT were measured and analyzed.【Result】The results showed that there were obvious temporal and spatial changes in the content of endogenous MT, 5-HT and 2-OHMel in different organs of plants under NaCl stress, and the MT content of roots reached the peak value after 7 days treatment, followed by the shoots, and the content of leaves were the lowest. With the prolongation of the stress time, the MT content in the roots decreased significantly, while the 5-HT content in the shoots increased. Compared with the only NaCl stress, the 5-HT content in the leaves, the MT content in the roots and the contents of 2-OHMel in the shoots and leaves increased significantly after root-applied MT. The shape of OJIP curve was significantly changed, Fm and leaf maximum photochemical efficiency (Fv/Fm) significantly decreased by 31.6% and 11.6%, the non-photochemical quenching (NPQ) was significantly increased, and the linear electron transport rate of PSI (ETR(I)) and PSII (ETR(II)) were significantly decreased under NaCl stress. While the Fm and Fv/Fm in leaves were reduced by 12.9% and 7.3%, the increase of K and J points in the OJIP curve was significantly reduced by 23.6% and 11.3%, and the utilization efficiency of the light linear and electron transfer rate is significantly improved under NaCl stress and MT treatment.【Conclusion】NaCl stress induced the inhibition of photosystem activity in grapevine leaves, but promoted the synthesis of MT in the plant. Photoinhibition was alleviated under MT treatment, root-applied MT promoted the metabolism and distribution of MT in various organs of plants, alleviated the damaged degree of photosynthesis of grapevine leaves by NaCl stress.
    Heterosis and Mixed Genetic Analysis of Green-Center Trait of Spray Cut Chrysanthemum
    ZHAO QianRu, ZHONG XingHua, ZHANG Fei, FANG WeiMin, CHEN FaDi, TENG NianJun
    Scientia Agricultura Sinica. 2018, 51(5):  964-976.  doi:10.3864/j.issn.0578-1752.2018.05.014
    Abstract ( 297 )   HTML ( 3 )   PDF (974KB) ( 167 )   Save
    References | Related Articles | Metrics
    【Objective】 Green-center trait is an important ornamental trait of spray cut chrysanthemum, and the study of heterosis and genetic basis of green-center trait will provide an invaluable guidance for breeding program of spray cut chrysanthemum with green center. 【Method】In this study, inheritance and heterosis analyses were carried out for three green-center traits of spray cut chrysanthemum, i.e. the score of inflorescence center color (referred to as the inflorescence center color value, the same as below), the green-center relative area, and the period of inflorescence center keeping green, respectively. They were based on phenotypic data of 81 F1 population derived from yellow-center chrysanthemum cultivar ‘Nannongfengshou’ (female parent) and green-center chrysanthemum cultivar ‘Nannonghongxia’ (male parent), and 70 F1 population derived from green-center chrysanthemum cultivar ‘Nannonghongyun’ (female parent) and green-center chrysanthemum cultivar ‘Nannongxiaoqingxin’ (male parent) by using single generation segregation analysis method of major gene plus polygene mixed genetic model. 【Result】 The coefficient of variation of the two F1 hybrids was 24.88%-90.76%. The variation degree of Cross Combination I (yellow-center × green-center) was generally higher than that of Cross Combination II (green-center × green-center), but the average of Cross Combination II was generally better than that of Cross Combination I. In addition, the predominance of the inflorescence center color value, the green-center relative area, and the period of inflorescence center keeping green from Cross Combination I were -0.14, -3.42, and 0.11, respectively. The period of inflorescence center keeping green was positive, whereas other indicators of heterosis were negative. The predominance of the inflorescence center color value, the green-center relative area, and the period of inflorescence center keeping green from Cross Combination II were -0.11 -10.61 and -1.02, respectively. The over-parent heterosis of the period of inflorescence center keeping green was -0.52, which was worse than those of parents. There were positive and negative super-individuals in the two groups. The green inflorescence center color of F1 in Cross Combination I and Cross Combination II were 3.70% and 2.86%, respectively. The paternal flower color and the color which was one level lower than maternal flower color accounted for a similar proportion in the offspring and the proportion was more than 20.00%. The inflorescence center color value, the green-center relative area, and the period of inflorescence center keeping green were controlled by two pairs of major genes. The inflorescence center color value showed the negative effect, whereas the other two indicators showed positive effect. Furthermore, the inflorescence center color value, the green-center relative area, and the period of inflorescence center keeping green were 98.64%-98.83%, 95.04%-96.54%, and 66.73%-92.52%, respectively. Finally, there was a significant positive correlation among the inflorescence center color value, the green-center relative area, and the period of inflorescence center keeping green. 【Conclusion】 The heterosis and transgressive segregation of inflorescence traits commonly existed in F1 hybrid progenies of chrysanthemum, so we could choose individuals that were beneficial to the breeding. The genetic potential of the green inflorescence center color was weak, and we choose the cultivars as pollen donors in order to increase the numbers of green-center offspring. In addition, the heritabilities of the inflorescence center color value, the green-center relative area, and the period of inflorescence center keeping green were high, which was suitable for the selection in early generation. Finally, the positive correlation among the indicators was useful green-center chrysanthemum breeding.
    FOOD SCIENCE AND ENGINEERING
    Effects of Heating Temperature and Time on Collagen Properties and Tenderness in Beef
    LIU JingJing, LEI YuanHua, LI HaiPeng, XIE Peng, WAN HongBing, HUANG CaiYan, SUN BaoZhong, ZHANG SongShan
    Scientia Agricultura Sinica. 2018, 51(5):  977-990.  doi:10.3864/j.issn.0578-1752.2018.05.015
    Abstract ( 488 )   HTML ( 7 )   PDF (5199KB) ( 1363 )   Save
    References | Related Articles | Metrics
    【Objective】 The purpose of this study is to explore the effect of collagen on the beef tenderness by increasing the heating temperature and prolonging the heating time, which provided the theoretical basis for the tenderness characteristics of high maturity beef in China. 【Method】 The bovine semitendinosus muscle was heated at 60, 70, 80, 90 and 100℃ water bath temperature, and prolong heating time to 30, 60, 90, 120 and 150 min. The shear force, cooking loss, moisture content, texture characteristics, mechanical strength of connective tissue, collagen content and thermal solubility of cooked samples were measured, and the treated muscle samples were observed using scanning electron microscopy. The changes in tenderness under different heat temperatures and times were analyzed and the key factors influencing the tenderness are obtained through the correlation analysis. 【Result】 With the increase of heating temperature and heating time, the shear force and the water moisture of bovine semitendinosus decreased, the cooking loss increased. The total collagen and insoluble collagen increased with the increase of heating temperature, the change of relative total collagen and insoluble collagen content was not significant with the increase of heating time. The content of soluble collagen and the solubility of the soluble collagen increased with the increase of the heating time, and the relative content of the hydroxy-lysine pyridine and the adhesion all increased, but the relative content of lysine pyridine, gumminess, chewiness, cohesion and resilience all reduced. With the increase of heating time, the shear force of beef was negatively correlated with the cooking loss (P<0.05), extremely positively correlated with the water content, hardness, cohesion, adhesiveness, resilience and chewiness (P<0.01).the shear force was extremely significant negatively correlated with the content of HP, total collagen, soluble collagen, insoluble collagen and collagen thermal solubility (P<0.01). The total collagen and insoluble collagen content were extremely significantly positively related with cooking loss (P<0.01). Hydroxy-lysine pyridine (HP) was extremely positively correlated with the adhesiveness and total collagen content (P<0.01), and significantly positively correlated with the elasticity, soluble collagen and insoluble collagen content (P<0.05), and significantly negatively correlated with gumminess and chewiness (P<0.05). There was a significant negative correlation between lysine pyridine (LP) and elasticity (P<0.05), and a significant positive correlation with cohesion (P<0.05), and an extremely positively correlation with resilience (P<0.01). Compared with the heating temperature, the heating time on beef tenderness showed more effect. Beef tenderness is dependent on collagen content and thermal solubility, HP, cooking loss, moisture content, hardness, cohesion, adhesion, resilience and chewiness; collagen content and thermal solubility are dependent on cooking loss and moisture content. Muscle gumminess, elasticity, resilience, cohesion, adhesiveness and chewiness are all related to covalent cross-linking, only except the thermal solubility of collagen. 【Conclusion】The edible quality of high maturity beef is largely dependent on heating time and collagen properties. Collagen effects on tenderness increased as heating time increased. The content of collagen, the collagen thermal solubility and the concentration of covalent cross-linking affected the tenderness by affecting texture characteristics of beef. The tenderness was improved with the prolonging of heating time, which was because the increase of content of collagen, covalent cross-linking, connective tissue strength weakened the effect of muscle fiber on tenderness.
    RESEARCH NOTES
    Enhancement of the Genetic Linkage Map Density of Tetraploid Based on SSR Markers
    TANG Lu, JIN MengYa, HUANG LinKai, ZHANG Xu, ZHAO XinXin, ZHANG XinQuan
    Scientia Agricultura Sinica. 2018, 51(5):  991-998.  doi:10.3864/j.issn.0578-1752.2018.05.016
    Abstract ( 297 )   HTML ( 6 )   PDF (1486KB) ( 609 )   Save
    References | Related Articles | Metrics
    【Objective】In order to obtain a high density genetic map of tetraploid orchardgrass previously established, we used EST-SSR and genomics-SSR markers to enhance the density of the genetic map. These results will be beneficial and helpful to orchardgrass selection and QTL analysis,especially QTL analysis of recessive genes.【Method】Based on the proposed test-hybridization strategy, an F1 population of 214 individuals derived from the cross between two Chinese orchardgrass cultivars–Kaimo (tall height plant, more tillers, broad leaves and early-maturing) and 01436 (dwarf, less tillers, narrower leaves and late-maturing) was used for map construction. 574 pairs of EST-SSR markers and 150 pairs of Genomic-SSR markers were selected as the screening primers. Five of the 214 progenies were randomly selected and amplified together with their parents. Amplified fragments were separated on 8% denatured polyacrylamide gels. The primers which could amplify clear bands and the presence of separated polymorphic were used for population and parental DNA amplification. The amplified results were statistically analyzed according to the marker type. According to the presence or absence of bands (with band count 1, or count 0), the amplification products of the DNA were statistically analyzed. According to theχ2 test, the marker which separation ratio was in accordance with 1﹕1 (Aaaa × aaaa or aaaa × Aaaa) and 3﹕1 (Aaaa × Aaaa) for genetic linkage map construction by using HighMap software.【Result】Finally, 31 pairs of EST-SSR primers and 17 pairs of Genomic-SSR primers were used for population and parental DNA amplification, The primer polymorphism percentage were 5.4%, 11.3% and 6.6%.A total of 169 clear bands were obtained, and 89 were used to construct the genetic linkage map of orchardgrass. There were 79 markers with Aaaa × aaaa or aaaa × Aaaa segregation types, 10 with Aaaa × Aaaa and the remaining 80 with distorted markers. A high-density linkage map of orchardgrass was constructed using 2,551 markers, which were distributed on seven linkage groups spanning 758.4 cM. The encrypted map including 4187 SNP markers, 84 SSR markers, the number of markers in the LGs from166 to709, with average 364. LG1 contains the largest maker with 709, while the LG7 was the least with 166. The sizes of the individual LGs ranged from 60.28 to 147.09 cM, with average inter-marker distances ranging 0.19—0.76 cM. The average distance between adjacent distance markers was reduced from 0.37 cM to 0.3 cM. Due to the change of marker density, the position of the markers distribution on each linkage group also changed greatly.  【Conclusion】 A high-density genetic linkage map of tetraploid Dactylis glomerata was reconstructed using 2551 markers, which were distributed on seven linkage groups spanning 758.4 cM. The new map added a number of SSR markers, which total length increased by 42.63 cM and average distance between adjacent distance markers was reduced from 0.37 cM to 0.3 cM.
    Spatial Distribution Characteristics of Wheat Grain Quality and Analysis of Factors Based on GIS
    SUN LiJuan, HU XueXu, LU Wei, WANG BuJun
    Scientia Agricultura Sinica. 2018, 51(5):  999-1011.  doi:10.3864/j.issn.0578-1752.2018.05.017
    Abstract ( 284 )   HTML ( 7 )   PDF (6885KB) ( 347 )   Save
    References | Related Articles | Metrics
    【Objective】The aim to the study is to explore the spatial and temporal distribution characteristics regularities of wheat grain quality and impaction factors.【Method】The Jimai 22 was selected because it was cultivated for long time and a wide range in China. And then by using geographical information systems (GIS) to select the optimal model, wheat grain quality spatial distribution of 6 provinces were drawn from 2010 to 2015. The key factors should be screened in water, temperature, light, longitude and latitude with correlation analysis and stepwise regression analysis during kernel formation stage.【Result】There were distinct differences in wheat grain quality around difference years and wheat production areas. The coefficient variation of wheat quality was the grain protein content>wheat hardness>test weight. The general spatial distribution trend of wheat hardness was low in the Northeast and high in the Southwest, and then the hardness was decreased year by year in the 6 years. Meanwhile, the spatial distributions of wheat hardness were different in those years, which were from west towards east, north to south and inner side towards outer side. In most years, the wheat hardness of strong gluten wheat region in northern part of North China (Ⅰ) and strong-medium gluten wheat region of Northern Huang-Huai Region (Ⅱ) was better than that of medium gluten wheat region of Southern Huang-Huai Region (Ⅲ). The wheat hardness was significant negative correlation with total rainfall at filling stage, total rainfall at maturity stage, mean light hours at maturity stage and latitude, moreover total rainfall at filling stage and latitude were main factors. The overall spatial distribution trend of test weight was low in Northeast and high in Southwest in those years. The test weight showed a slowly increasing trend year by year, but the test weight of 2013 was below to other years. While the wheat weight of westward and center in the Ⅱ was better than other regions. The test weight had the significant positive correlation with diurnal temperature range at maturity stage, mean temperature at maturity stage, ≥10℃ effective cumulative temperature at maturity stage and diurnal temperature range at filling stage, meanwhile diurnal temperature range at maturity stage was the main factor. The general spatial distribution trend of the grain protein content was high in Northeast and low in Southwest in the 6 years. The grain protein content had downward trend with those passing years. Most of years, the distribution of the protein content was zonal, which in the north area was integrally higher than south with the main factor latitude.【Conclusion】The main factors affecting the spatial and temporal distribution characteristics of kernel quality were total rainfall at filling stage, diurnal temperature range at maturity stage and latitude. The wheat hardness showed a decreasing trend for the increasing of total rainfall at filling stage year by year. And then the spatial distributions of wheat hardness were manifold, because of irregular change with total rainfall at filling stage and different latitude. Due to change of diurnal temperature range at maturity stage, the spatial distributions of wheat weight had a slowly increasing, and the test weight had change at different region year by year. The grain protein content had increasing trend for the rising of latitude, which had basically consistent distributions in most year. The junction area of Hebei province, Shandong province and Henan province with lower total rainfall at filling stage and higher diurnal temperature range at maturity stage, should be conducive to improving grain quality of wheat, where belong to strong gluten wheat and medium gluten wheat producing areas in Huang-Huai Northern region.
    SHORT COMMUNICATION
    A New Animal Infectious Disease, Moschus Chrysogaster Viral Hemorrhagic Disease
    BAO ShiJun, XING XiaoYong, DING XiaoQin, GAO Xiang, AN Kai, FU Xiao Ping, XUE HuiWen
    Scientia Agricultura Sinica. 2018, 51(5):  1012-1012.  doi:10.3864/j.issn.0578-1752.2018.05.018
    Abstract ( 352 )   HTML ( 11 )   PDF (189KB) ( 312 )   Save
    Related Articles | Metrics