Scientia Agricultura Sinica

Expression on Profiling of Rice PP2Ac Type Phosphatase Proteins in Seedlings Under Salt-stressed Conditions

LIU Zhao, JIA Lin, JIA Meng, GUAN Ming-Li, CAO Ying-Hao, LIU Li-Juan, CAO Zhen-Wei, LI Li-Yun, LIU Guo-Zhen

Scientia Agricultura Sinica. 2012, 45(12): 2339-2345. doi:10.3864/j.issn.0578-1752.2012.12.001

Abstract ( 867 )

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【Objective】The protein expression profiling and the mechanism of rice salt-tolerance were studied.【Method】 The expression patterns of five rice phospatase 2A catalytic subunits (PP2Ac) in seedlings under salt-stressed conditions were surveyed by Western blotting via antibody-based proteomics strategy. 【Result】 The results indicated that the expression of OsPP2Ac-4 protein was up-regulated in salt-tolerant rice variety Lansheng, and the expressions of OsPP2Ac-2, OsPP2Ac-3 and OsPP2Ac-5 were up-regulated in salt-sensitive rice variety 9311, while the expression of OsPP2Ac-4 was down-regulated in 9311. The expression of PP2Ac proteins was stable and in a similar level for Lansheng and 9311 under normal growth conditions, but the abundance variations were occurred only under salt-stressed conditions. Based on the Massively Parallel Signature Sequencing (MPSS) data derived from salt-stressed rice seedlings, it was found that the transcription of OsPP2Ac-2, OsPP2Ac-3 and OsPP2Ac-5 were down-regulated by comparison with control seedlings without salt treatment.【Conclusion】Four salt stress-related rice PP2Ac proteins were identified.

Epistatic Effects and QE Interaction Effects of QTLs for Two-Seed Pod Length and Width in Soybean

YANG Zhen, PEI Yu-Feng, XIE Sheng-Nan, LIU Chun-Yan, JIANG Hong-Wei, HAN Xue, XIN Da-Wei, CHEN Qing-Shan, HU Guo-Hua

Scientia Agricultura Sinica. 2012, 45(12): 2346-2356. doi:10.3864/j.issn.0578-1752.2012.12.002

Abstract ( 842 )

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【Objective】The objective of this study was to investigate the epistatic effects and QE interaction effects of QTLs for two-seed pod length and two-seed pod width.【Method】In order to find out these results, a F2:14-F2:18 RIL population containing 147 lines derived from a cross between Charleston as female parent and Dongnong594 as male parent were used in this experiment. A genetic linkage map was constructed with 164 SSR primers screened in two parents and amplified in 147 lines population. QTLs and epistatic effects and QE Interaction effects of QTLs were located on one site in five years with a mixed linear model (QTLmapper1.6) . QTLs for these were detected in a five-year experiment with the recombination inbred lines (RIL) population derived from a cross between Charleston and Dongnong 594. 【Result】Eight two-seed pod length QTLs and six two-seed pod width with additive effects were detected, the additive effects contribution rate were 27.2% and 16.27%, respectively, the general contribution of interaction between QTLs and environment were 10.19% and 12.18%. Nine pairs of two-seed pod length QTLs with epistatic effects were found in the RIL, accounting for 9.02% of the general phenotypic variation, and eight pairs of two-seed pod width QTLs accounting for 8.81% of the general phenotypic variation.【Conclusion】The results indicated that the epistatic effects and the environmental factor played an important role in the inheritance of two seed-pod length and width in soybean. Therefore, both major and minor QTLs should be considered in the improvement in soybean breeding.

Current Situation of Research on Transgenic Crops with Herbicide Tolerance and Development Prospect

QIU Long, MA Chong-Lie, LIU Bo-Lin, ZHANG Wang-Gen

Scientia Agricultura Sinica. 2012, 45(12): 2357-2363. doi:10.3864/j.issn.0578-1752.2012.12.003

Abstract ( 1094 )

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To improve crop productivity, it is important to control weeds in the fields during plant growth. Facts have proved that the cultivation of transgenic crops with herbicide tolerance is an effective measure to reduce the production cost and to increase the output compared to conventional methods. This article aims to review the principle, application and safety of transgenic plants with herbicide tolerance in the world. Furthermore, the prospect of transgenic crops with herbicide tolerance was forecasted.

Process-Based Simulation Model for Growth Dynamics of Plant Type Index in Wheat

ZHANG Wen-Yu, TANG Liang, YAO Xin-Feng, YANG Yue, CAO Wei-Xing, ZHU Yan

Scientia Agricultura Sinica. 2012, 45(12): 2364-2374. doi:10.3864/j.issn.0578-1752.2012.12.004

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【Objective】This study was designed to explore the dynamic changing characteristics of wheat (Triticum aestivum L.) plant type index and the effects of planting density on plant type index.【Method】Based on the field experiments with three cultivars (Aikang 58 with erect leaf, Yangmai 12 and Yangmai 16 with flat leaf) and three planting densities in wheat, the time-course measurements were carried out on the indices of leaf type and stem type at main growing stages of wheat, and then the dynamic changing patterns of plant type indices and the effects of planting density on the dynamics of plant type indices in wheat were analyzed and simulated.【Result】The results indicated that the layer LAI of different plant-type cultivars had a trend of “middle layer> upper layer> lower layer”, and the layer LAI was gradually concentrated in the middle or upper layer with the growing progress. In addition, the larger LAI of the middle or upper layer was observed on high population density. The significant differences of plant height component index (the ratio of the length of rachis and penultimate internodes to plant height, IL) between high and low population densities were observed. The plant height component index (the ratio of the length of n internode to the length of n internode adding (n-1) internode, In) of different plant-type cultivars were all decreased first and increased later from lower to higher leaf positions. In addition, the remarkable effect of planting density was observed on In of upper internode. As for Aikang 58, a relatively constant LOV with a slight “up-down-easing down” trend was observed. As for Yangmai 12, the change pattern of LOV was in “gentle-decrease-gentle” trend. As for Yangmai 16, a trend of “gentle-decrease-increased slightly” was showed. Based on the analysis of plant type index dynamics and the existing morphological model, the dynamics of layer LAI was simulated by using the methods of canopy cutting and leaf area integration, and the dynamics of the plant height component index and LOV were simulated by using combined morphological parameters. In addition, the comprehensive plant type component index was constructed by integrating different morphological indices, and reflected the dynamic changes of the leaf type and stem type synthetically. Testing of the dynamic models of layer LAI, plant height component index and LOV with independent dataset showed that the average RRMSE values of layer LAI and LOV were 17.44%, 7.64%, and 10.66%, respectively.【Conclusion】The results indicated a good performance and reliability of models for predicting plant type index in wheat. The model can not only provide technical supports for the simulation of canopy structure in wheat, but also lay a foundation for the simulation of light distribution and photosynthesis within wheat canopy.

Screening of Environment-friendly Cropping Mode in the Northern Region of Erhai Lake

TANG Qiu-Xiang, LIU Hong-Bin, LEI Bao-Kun, DI Li-Mei, HU Wan-Li, LUO Xin-Hua, ZHANG Ji-Zong, REN Tian-Zhi

Scientia Agricultura Sinica. 2012, 45(12): 2375-2383. doi:10.3864/j.issn.0578-1752.2012.12.005

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【Objective】Screening of intercropping patterns suitable for local planting was studied from the standpoint of economic benefit and environmental benefit.【Method】A field plot experiment was carried out on Luoshijiang edge of the northern region of Erhai Lake where Zhaoyi village of Shangguan town is situated; Nutrient balance, economic benefits, crop quality and soil nutrient residue status of intercropping patterns were analyzed after samples were tested in the laboratory. The four factors influencing economic and environmental benefits were identified as the index set in the intercropping by using methods of subjective weight and objective weight, and these factors are revenue, quilty of commodity, inorganic nitrogen in soil and rapidly available phosphorus in soil. Different intercropping patterns were evaluated by using fuzzy comprehensive evaluation method. 【Result】The results showed that the score of Vicia fava and garlic intercropping mode with area of vicia fava and garlic ratio of 1﹕3 was the highest in the 14 intercropping modes, and it was an environment-friendly cultivation mode because both economic and environmental benefits were higher than other modes. Followed by the onion and garlic intercropping mode with area of onion and garlic ratio of 1﹕3, and its score was 0.624, its economic benefits was better than others, but the environmental effect slightly worse than others. Ryegrass and garlic intercropping mode with area of ryegrass and garlic ratio of 1﹕3, and it was ranked the third for the score was 0.609, optimum environmental benefits, but the input was lower. The lowest score of the rape and garlic intercropping mode with area of rape and garlic ratio of 1﹕1, and its score was 0.084, its economic and environmental benefits was lower because of the large differences in plant height.【Conclusion】In this study, the appropriate local environment-friendly planting mode was Vicia fava and garlic ratio of 1﹕3.

Constuction and Evaluation of ATMT Mutant Library of Setosphaeria turcica

WANG Mei-Juan, LI Po, WU Min, FAN Yong-Shan, GU Shou-Qin, DONG Jin-Gao

Scientia Agricultura Sinica. 2012, 45(12): 2384-2392. doi:10.3864/j.issn.0578-1752.2012.12.006

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【Objective】 The objective of this study is to use Agrobacterium tumefaciens-mediated transformation (ATMT) to mutate the genes of Setosphaeria turcica and construct ATMT mutant library, which will lay a foundation for illuminating the pathogenesis of S. turcica at molecular level. 【Method】A. tumefacien with binary recombination vector was transformed into S. turcica, and the mutants were screened by hygromycin B and PCR technology. Based on the methods, a preliminary ATMT mutant library was constructed. Some mutants were selected randomly and analysed about the colony morphologies, mycelium and conidium development, and pathogenicity.【Result】A total of 1 265 T-DNA insertion mutants were obtained in this experiment. Hygromycin B resistance screening and PCR technology were used to confirm 36 mutants, which were selected randomly from the mutant library. The results showed that hygromycin phosphotransferase genes had been integrated into wild-type genome of S. turcica and the mutants were stable in their characteristics of genetics. Compared with wild-type strains, most of the mutants did not changed their colony morphologies and growth rates, only minorities of the mutants varied in their characteristics, in which 13.8% strains slowed down their growth rate obviously, 16.7% strains accelerated their growth rate distinctly, about 5.6% strains altered their shapes of conidia, 13.5% strains reduced the number of conidia, 16.6% strains changed their germination rate evidently, and 1 strain reinforced its pathogenicity, accounting 2.8% in all selected strains.【Conclusion】 ATMT mutant library of S. turcica was constructed and some mutants were analysed primarily. The study will lay a foundation for cloning genes related to growth, development and pathogenicity of S. turcica in the future.

The Characteristics and Biological Function of Glucosamine-6-phosphate-N-acetyltransferase in Locusta migratoria

ZHANG Huan-Huan, ZHANG Xue-Yao, LIU Xiao-Jian, MA 恩Bo, ZHANG Jian-Zhen

Scientia Agricultura Sinica. 2012, 45(12): 2393-2403. doi:10.3864/j.issn.0578-1752.2012.12.007

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【Objective】The objective of this study is to investigate the expression characteristics and biological function of glucosamine-6-phosphate-N-acetyltransferase (GNA) gene of Locusta migratoria, and to explore the mechanism of chitin synthesis and develop new effective pesticides.【Method】The cDNA sequence of LmGNA was searched from locust EST database by using bioinformatics methods, and multiple alignment was performed for sequence identity analysis. The developmental expression of LmGNA from the 1st to 7th day of the 5th instar nymph stage and the tissue specific expression at the 2nd day of the 5th instar nymph were tested by Real-time PCR. Recombinant LmGNA protein was expressed in transformed E. coli BL21(DE3) with pET-28a(+) vector containing LmGNA ORF, and then purified by Ni-nitrilotriacetic acid (NTA) affinity column and the enzyme activity was analyzed by using spectrophotometer. To better understand the function of LmGNA, RNAi was performed by injection dsRNA of LmGNA into locust nymphs.【Result】 The amino acid sequences of GNAs from different species showed a high identity. The residues responsible for binding substrate GlcN6P were exactly the same, which suggested GNAs were highly conserved among different species. Tissue specific expression pattern indicated that LmGNA was mainly expressed in integument, fat body and muscle at the 2nd day of the 5th instar nymphs. The developmental expression pattern from the 1st to 7th day of the 5th instar nymph stage showed that LmGNA was highly expressed after new molting, and then declined at the following days of the same stadium. The recombinant LmGNA protein was successfully heterologous expressed in E. coli as a fusion protein. The optimal enzyme activity was detected at 37-50℃ and pH values 8.0-9.5. The Km value for D-GlcN6P was 42.43 μmol•L-1 when the concentration of Acetyl-CoA was 200 μmol•L-1, in contrast, the Km value for Acetyl-CoA was 133.60 μmol•L-1 when the concentration of D-GlcN6P was 200 μmol•L-1. RNAi results indicated that the mRNA of LmGNA was silenced effectively, however, ecdysis and development of locust were not affected.【Conclusion】GNAs from different species were conserved with high sequence identities. The recombinant LmGNA protein expressed in E. coli presented glucosamine-6-phosphate-N-acetyltransferase activity. The mRNA expression of LmGNA was significantly down-regulated by RNAi, but no visible block of ecdysis or development was observed. These data suggested that N-acetylglucosamine kinase, a reparing pathway could be involved in producing N-acetylglucosamine-6-phosphate (GlcNAc6P) instead of GNA for chitin biosynthesis.

Identification of Fungus Lecanicillium psalliotae and Its Colonization in Different Life Stages of Meloidogyne incognita

CAO Jun-Zheng, WU Xia, LIN Sen

Scientia Agricultura Sinica. 2012, 45(12): 2404-2411. doi:10.3864/j.issn.0578-1752.2012.12.008

Abstract ( 931 )

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【Objective】 The objective of this study is to investigate the control potential of egg-parasitic fungi Lecanicillium psalliotae against root-knot nematodes as an useful biological control agent.【Method】The fungus strain CGMCC5329 was isolated from eggs of Meloidogyne incognita infecting sponge gourd in Chengyang, Qingdao, Shandong Province. Based on morphological characters and molecular analysis of ITS-rDNA, the strain was identified as L. psalliotae. Colonization of L. psalliotae in different life stages of M. incognita was observed by microscope. 【Result】The fungus colonized in different life stages of M．incognita including eggs, juveniles and females, and demonstrated the great suppression in hatch of egg masses. The infection pegs and fungal networks on egg were observed on surface of infected eggs which showed a wrinkled and shrunken appearance. The embryonic development was arrested by the fungal invasion and high vacuolation was also observed. In some cases the conidiating hyphae were also seen outside the egg surface. The egg parasiting rate by fungi was 85.76% on 6th day. The inhibition in hatch of egg masses was 91.41% on 15th day．The 2nd stage juveniles were penetrated with networks of hyphae and the body were full of fungal hyphae. The juvenile parasitic rate by fungi was 79.23% on 5th day. The extensive network and infection pegs were formed on females parasited with fungi which resulted in body deformation, sometimes the contents extravasated.【Conclusion】 L．psalliotae CGMCC5329 not only colonizes the sedentary females and eggs, but also infects 2nd stage juveniles. It could be used as an useful biological control agent against root knot nematodes.

Effect of Different Additives on Decomposition of Rice Straw

DI Xiu-Cai, LIU Ming, LI Zhong-Pei, XU Yang-Chun

Scientia Agricultura Sinica. 2012, 45(12): 2412-2419. doi:10.3864/j.issn.0578-1752.2012.12.009

Abstract ( 713 )

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【Objective】The objective of the experiment is to study the effect of different chemical additives on the changes of physical and chemical properties, nutrient, humic substances and germination index (GI) of decomposition of rice straw and help reasonable use of organic resources theoretically and technically. 【Method】In the present study, rice straw was used as organic material, EM microorganism agents and chemical additives, such as FeSO4, Na2SO4, lime and alkali slag, were mixed and cultured in the incubator. Changes of pH, organic matter, NPK nutrient and humic acid of decomposition of rice straw were analyzed. The effect of extracts of decomposition on GI of turnip seeds was also determined.【Result】After 54 days, the results showed that the pH values of the decomposition in each treatment were 8.17 to 8.65, slightly alkaline. Changes of physical properties of decomposition also indicated that straw decomposed thoroughly. The soil organic carbon and nutrient contents in treatments with 10% alkali slag, 3% FeSO4 and 10% alkali slag combined with 3%FeSO4 were higher than that in other treatments. Humic substances contents in treatments with 3% FeSO4 and 10% alkali slag combined with 3% FeSO4 were 76.1 and 78.0 g•kg-1, respectively, which were significantly higher than those in other treatments. Chemical additives also improved the quality of humic substances. In treatments with 10% alkali slag and 10% lime, the humic acid contents were 47.7 and 50.3 g•kg-1, respectively, and the HA/FA ratios were more than 2. In treatments with 10% alkali slag, 3% FeSO4, and 10% alkali slag combined with 3% FeSO4, GI was higher than 80% indicating that these treatments could not only promote the decomposition of rice straw, but also eliminate the toxicity of the decomposition.【Conclusion】 Above results indicated that alkali slag and FeSO4 could significantly promote straw decomposition efficiently and improve the quality of decomposition.

Effects of Different Irrigation Methods and Fertilization Measures on Soil Respiration and Its Component Contributions in Cotton Field in Arid Region

ZHANG Qian-Bing, YANG Ling, WANG Jin, LUO Hong-Hai, ZHANG Ya-Li, ZHANG Wang-Feng

Scientia Agricultura Sinica. 2012, 45(12): 2420-2430. doi:10.3864/j.issn.0578-1752.2012.12.010

Abstract ( 811 )

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【Objective】It is of great significance to explore the effects of different irrigation methods and fertilization measures on soil carbon balance in cotton field during cotton growth season in arid region, and to compare the effects of different management practices on soil carbon sequestration intensity in cotton field.【Method】Two-factor experiments with two irrigation methods and four fertilizer treatments were conducted during cotton growth period. Drip irrigation and flood irrigation were arranged as two different irrigation methods and organic manure (OM), N P K fertilizer (NPK), combined application of NPK fertilizer and organic manure (NPK+OM) and no fertilization (CK) were arranged as four fertilizer treatments. Soil respiration rate in cotton field was measured by LI-8100 automated soil CO2 efflux system and root contribution of soil respiration was detected by root exclusion method. Soil carbon sequestration intensity in cotton field under different irrigation methods and fertilization measures was analyzed by calculating net ecosystem productivity (NEP). 【Result】 Under the conditions of different irrigation methods and fertilization measures, seasonal variation of cropland soil respiration rate showed an increase at first, then followed a declining trend with air temperature change. Soil respiration rate reached a peak in mid-July and then reduced to the minimum in mid-October after cotton harvest. Soil carbon emission under drip irrigation was larger than that under flood irrigation, and under the same irrigation condition, the soil carbon emission with NPK+OM treatment was the highest, then with OM, CK, NPK in turn. The ratio of root respiration contribution to soil respiration was fluctuated between 36.38% and 58.74% under drip irrigation method, whereas between 33.73% and 52.03% under flood irrigation method. Root respiration contribution was the highest at the bolling stage. During the whole growth period, the root respiration contribution under drip irrigation and flood irrigation was averagely 48.05% and 44.31%, respectively. The order of net primary productivity (NPP) of cropland was NPK+OM＞NPK＞OM＞CK under different irrigation methods in the whole season. Cotton field was carbon sink under different management practices in the whole season, and the intensity of carbon sink under drip irrigation was stronger than that under flood irrigation. Under the same irrigation condition, the order of the intensity of carbon sink was NPK+OM＞NPK＞OM＞CK. Under the condition of interaction between irrigation method and fertilization measure, the carbon sink intensity was the strongest under drip irrigation method and NPK+OM.【Conclusion】In arid region, cotton production using cropland management measures, such as water saving technology of drip irrigation under mulch, combined application of NPK fertilizer and organic manure and straw returning, could not only increase soil organic carbon content, fertilize the soil fertility and improve cotton yield, but also promote to fix carbon and reduce discharge.

Multiple Analysis of Relationship of Agronomic Traits and Yield Formation in Ginger

LI Xiu, XU Kun, GONG Biao, CAO Bi-Li, WANG Zhong-Bin

Scientia Agricultura Sinica. 2012, 45(12): 2431-2437. doi:10.3864/j.issn.0578-1752.2012.12.011

Abstract ( 928 )

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【Objective】 The purpose of this study was to provide academic evidence for germplasm evaluation and innovation of ginger, and identify the primary indexes of yield by investigating the variation of agronomic traits of ginger.【Method】The correlation, path analysis, principal components analysis and multiple linear regression analysis were conducted, whilst integrated the growth status of ginger, and applied critical-path analysis, to identify the primary indexes of ginger yield. 【Result】The results showed that the variation coefficient of agronomic traits of ginger reached 11.4%-51.3%, and the yield had a extremely significant correlation with stem diameter, stem FW, plant height, leaf FW and root FW, but a significant or extremely significant negative correlation with rhizome DM content and branch number. Plant height, stem diameter, root FW, stem FW and rhizome DM content were named as determinative morphological factors of high-yielding varieties, and branch number, leaf number and ginger bulb number were named as determinative morphological factors of low-yielding varieties. The determination coefficient of four factors selected by multiple linear regression analysis to ginger yield model was 0.8194.【Conclusion】The major determining factors of ginger yield were rhizome DM content, leaf FW, stem diameter and stem FW. The high yield varieties had thickest stem, fewer branch number, thicker leaf, developed assimilation system, and lower rhizome DM content.

Analysis of Leaf Volatiles from Crabapple(Malus sp.) Individuals of Different Juvenile Lengths

WU Man, SHEN Xiang, WANG Chao, DONG Yan, HAN Tian-Tian, WANG Rong

Scientia Agricultura Sinica. 2012, 45(12): 2438-2446. doi:10.3864/j.issn.0578-1752.2012.12.012

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【Objective】The aim of this experiment was to analyze the leaf volatiles of crabapple (Malus sp.) individuals at different juvenile lengths, and obtain their particular leaf volatiles, and provide reference for finding out a new breeding method.【Method】Volatiles of leaves from eight different crabapple individuls were evaluated with the method of head space-solid phase micro-extraction and gas chromatography - mass spectrometry (HS-SPME-GC-MS).Volatiles profiles of them were then compared.【Result】Eighty-four kinds of volatiles were detected with varied contents found in different individuals. The major leaf volatiles were 2-fluoro-acetamide, (Z)-3-Hexen-1-ol, diethyl phthalate and (Z)-3-hexen-1-ol acetate. Ten identical compositions including 3,7-dimethyl-1,3,7-octatriene, decanal, diethyl phthalate, 2,6,10-trimethylpentadecane, 2,6,10-1-tetradecanol; 2,6,10,14-tetramethyl pentadecane, hexadecane, 1-dodecanol;2,6,10,15-tetramethyl heptadecane and Phthalic acid, diisobutyl ester were detected.【Conclusion】Leaf volatiles differ in eight crabapple individuals. But they are all based on esters and hydrocarbons, and the highest content is 3-Hexen-1-ol, acetate. The specific volatiles in the precocious crabapples are (2Z)-2-Penten-1-ol, acetate. (E)-cyclobutane, 1,3-butadienyl and 5,5-dibutylnonane.

Comparison of Factors Influencing Noodle Sensory Qualities

ZHANG Bo, WEI Yi-Min, LI Wei-Jin

Scientia Agricultura Sinica. 2012, 45(12): 2447-2454. doi:10.3864/j.issn.0578-1752.2012.12.013

Abstract ( 1177 )

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【Objective】In order to compare the influence of wheat flour and making process on sensory qualities of noodle, 9 wheat flour samples were selected. 【Method】The effects of water addition, mixing time, resting time and the sheeting ratio on sensory qualities of noodle, with every type of flour, were studied using quadratic orthogonal rotation combination design. 【Result】The results showed that the coefficient of variations (CV) of color, springness, hardness, coherence, smoothness, total score and appearance decreased gradually. The proportions, that affect on the color, appearance, hardness, coherence, springness, smooth and total score of noodle, of flour sample were 95.18%, 80.64%, 45.96%, 70.94%, 56.30%, 38.64% and 79.17%, respectively. The total score of noodles making of Gaojin, Aikang58 and Xiaoyan6 flour samples were more than 75. The CV of total score of noodle making of Gaojin, Aikang58 and Xiaoyan6 flour samples were relatively low（<5%）. 【Conclusion】It is concluded that color, springness and hardness of noodle were influenced by wheat flour and making process among sensory qualities. Noodle making stability was different among wheat flours. Compared with making process, the proportion of wheat flour influencing color, appearance, coherence, springness and total score of noodle is more than 50%. The water addition, mixing time and resting time mainly influence the springness and hardness of noodle.

Effects of Supplement of Tryptophan on Behavior and Related Hormones in Piglets After Mixing

LIU Hua-Wei, SHI Bao-Ming, LOU Lei, WANG Hong

Scientia Agricultura Sinica. 2012, 45(12): 2455-2461. doi:10.3864/j.issn.0578-1752.2012.12.014

Abstract ( 892 )

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【Objective】The objectives of this experiment were to evaluate the effects of dietary tryptophan on behavior, concentrations of relative hormones and expression of 5-HT2A mRNA in piglets after mixing. 【Method】A total of 144 weaning piglets at 28 d of age with initial average weight at (8.00±0.25) kg were assigned to three groups randomly. Each group included 6 replicates with 15 piglets each. The control group was fed with the basal diet including 0.21% tryptophan, the trentment groups (treatment groupsⅠ and Ⅱ) with basal diets plus 0.1% and 0.2% tryptophan, respectively. Piglets were mixed after diet introduction for 28 d. The aggressive and daily behavior were recorded after mixing and the levels of salivary cortisol , hypothalamic 5-HT and 5-HT2A mRNA were determined. 【Result】After mixing, piglets fed with supplemental tryptophan had less time and number of fights and spent more time lying and less time standing (P＜0.05) than pigs fed with the control diet. There were no significant differences in food gathering and sitting behavior among groups (P＞0.05). As the levels of dietary tryptophan increased, the concentrations of salivary cortisol decreased significantly (P＜0.05), whereas the concentrations of hypothalamic 5-HT increased significantly (P＜0.05). The expression of hypothalamic 5-HT2A in piglets decreased gradually as the levels of dietary tryptophan increased, however, the difference was only significant between the control group and the treatment group Ⅱ (P＜0.05).【Conclusion】Surplus 0.1% and 0.2% tryptophan that exceeded the standard requirement for piglets can increase the concentrations of hypothalamic 5-HT concentrations, modify the expression of hypothalamic 5-HT2A mRNA, decrease the concentrations of salivary cortisol, and also alleviatesusceptibility to stress in piglets after mixing.

Effects of Melatonin on the Expression of Bcl-2 and Bax Genes in Skin of Cashmere Goat

LIU Hui, ZHANG Yan-Jun, LI Jin-Quan, ZHANG Wen-Guang, WANG Zhi-Xin, ZHANG Yong-Bin, HE Yun-Mei, JIANG Zai-Ping, LI Chun, FENG Lin, WANG Rui-Jun

Scientia Agricultura Sinica. 2012, 45(12): 2462-2467. doi:10.3864/j.issn.0578-1752.2012.12.015

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【Objective】The present study was aimed to research the effects of melatonin on the expression of Bcl-2 and Bax genes in the skin of Inner Mongolia Cashmere goat, then discuss the relationships between Bcl-2, Bax, and melatonin and the growth and apoptosis of cashmere goat. 【Method】 Eight Inner Mongolia Cashmere goats, with the same age, sex and liveweight were chosen. Four of them were treated with melatonin, the rest were used as control. Total RNA of skin was extracted, and expression of Bcl-2 and Bax genes were analyzed by real-time PCR. 【Result】 The changing characteristics of Bcl-2/Bax coincided with the growth rhythm of cashmere of Inner Mongolia Cashmere goat. Melatonin had no significant effects on expression of Bcl-2 gene (P>0.05), but significantly up-regulated the Bax gene (P<0.01). 【Conclusion】 Melatonin down-regulated the ratio of Bcl-2/Bax in the skin of Inner Mongolia Cashmere goat, which promoted the apoptosis and accelerated the metabolism.

Analysis of Duck CD8α Gene Promoter and Its Transcriptional Activity

XU Qi, CHEN Yang, HUANG Zheng-Yang, ZHANG Yang, CHEN Chang-Yi, ZHAO Rong-Xue, LI Xiu, DUAN Xiu-Jun, CHEN Guo-Hong

Scientia Agricultura Sinica. 2012, 45(12): 2468-2473. doi:10.3864/j.issn.0578-1752.2012.12.016

Abstract ( 1014 )

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【Objective】 This experiment was conducted to explore the function determination and expression regulation of CD8α gene in ducks by analysis of transcriptional activity of its promoter. 【Method】 The promoter missing mutants were constructed（-625/-1 bp, -1110/-1 bp, -1413/-1 bp, -2151/-1 bp）accroding to the sequence of CD8α gene promoter, and then subcloned into pGL3 basic vectors to construct luciferase reporter gene vectors, respectively. The recombinant vectors were transfected into DT40 cells with Lipofectamine 2000, and the transcriptional activities were detected. 【Result】Results of the study indicated that CD8α gene promoter had obviously promoter activity. The sequence from -1 110 to -625 bp of 5′ flanking region had the strongest promoter activities, including two positive (-625/-1 bp and -1 110/-625 bp) regulatory domains. 【Conclusion】 The luciferase reporter gene eukaryotic expression vector with CD8α gene promoter sequences was constructed successfully using deletion mutation and its major regulatory regions were found, which play an important role for analyzing the promoter activity and transcriptional regulation mechanism.

Bovine Embryonic Stem Cells Culture on Mixed Feeder Layers with Mouse and Bovine Embryonic Fibroblasts in Vitro

CONG Shan, WANG Rui, WEN Jian-Xun, HAO Fei, LI Shuo, LIANG Hao, LIU Dong-Jun

Scientia Agricultura Sinica. 2012, 45(12): 2474-2481. doi:10.3864/j.issn.0578-1752.2012.12.017

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【Objective】The aim of this study was to establish a suitable culture environment for bovine embryo stem cell.【Method】Bovine and mouse fibroblast cells were treated for 2.0-3.0 h with mitomycin C, respectively. Mixed feeder layer was that cells which were mixed according to 1﹕0, 1﹕1, 1﹕2, 2﹕1, 0﹕1 were cultured in the center plate coated by gelatin at 2-2.5×104 per well. Growth states of bovine embryonic stem cells were observed in different feeder layers and undifferentiated phenotypes were detected, including expression of alkaline phosphatase, and presence of OCT-4, SOX2, NANOG and cell marker OCT-4, SSEA-1. Without feeder layer, bovine embryonic stem cell differentiation was observed in vitro.【Result】Comparison of bovine embryonic stem cell growth state on different feeder layers, the clonal morphology on the mixed feeder layer was significantly better than that on the mouse embryonic fibroblast feeder layer or bovine embryonic fibroblast feeder layer. When mouse embryonic fibroblasts and bovine embryonic fibroblasts were mixed at a ratio of 1﹕1 bovine embryonic stem cells accumulated significantly and cloning edge was clear, obvious and full. Expression of alkaline phosphatase, antigen of OCT-4 and SSEA-1 were strongly positive. Specific bands of OCT-4, SOX2 and NANOG mRNA appeared, respectively. Bovine embryonic stem cells on mixed feeder layer was able to form embryoid bodies.【Conclusion】Compared with conventional feeder layers prepared by mouse embryonic fibroblasts or bovine embryonic fibroblasts, the mixed cells feeder layer mixed at a ratio of 1﹕1 may be better suitable for bovine embryonic stem cell culture in vitro and obtain better bovine rembryonic stem cell clonal morphology.

Study on the Susceptibility of Turtledoves to Avian Influenza Virus Subtype H9N2 and its Receptor

DING Pei-Pei, LIU Yue-Huan, CHEN Ming-Yong, HAN Chun-Hua, LIN Jian, HAN Jing-Wen, PAN Jie

Scientia Agricultura Sinica. 2012, 45(12): 2482-2490. doi:10.3864/j.issn.0578-1752.2012.12.018

Abstract ( 855 )

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【Objective】 The susceptibility of turtledove to H9N2 subtype avian influenza virus and the type and distribution of influenza virus receptors in the respiratory tract epithelium of turtledove were studied. 【Method】 Eight turtledoves and eight SPF chickens were inoculated with A/Chicken/Beijing/2/2009 H9N2 via oculonasal routes at a dose of 5×104EID50 per bird. In addition to observation of clinical signs and gross pathological changes and histopathological changes, the location of the viral antigen and antibody detection were used. Influenza A matrix protein was observed by immunohistochemistry straining. The type of SAα2, 6Gal and SAα2, 3Gal linkage on these animals’ trachea and larynx epithelium cells were detected by digoxigenin-labeled lectin staining. 【Result】 On day 5 post inoculation, no abnomal clinical signs and pathological changes were found in the turtledoves and SPF chickens. The epithelium was found with different degrees of swelling in the turtledove’ larynx , upper trachea, middle trachea and lower trachea. The virus positive particles were detected in turtledoves’ upper trachea, middle trachea , lower trachea and lung epithelium with the method of immunohistochemistry; H9N2 AIV was isolated from turtledoves, and the positive rate of turtledoves’ nasopharyngeal swab was 75% (6/8), that of SPF chickens’ was 100% (8/8). On 14th day post inoculation, HI antibody was detected, and the positive rate of turtledoves’ was 80% (4/5), that of SPF chickens was 100 (5/5). SAα2, 3Gal and SAa2，6Gal were both detected on turtledove’s larynx, upper trachea, middle trachea and lower trachea 【Conclusion】 The turtledoves are susceptible to A/Chicken/Beijing/2/2009, and there are both SAα2, 3Gal binding avian influenza virus and SAα2, 6Gal binding human influenza virus on turtledove’s larynx , upper trachea, middle trachea and lower trachea.

Cloning, Prokaryotic Expression of Echinococcus granulosus Heat Shock Protein 70 and Preparation of It’s Antiserum

ZHAO Li, CHEN Hao-Fei, ZHANG Wen-Bao, MA Zheng-Hai, ZHANG Zhuang-Zhi, ZHANG Xu, GU Nu-尔?Tu-尔Xun, MI Xiao-Yun, JIN Ying-Hong, XUE Jing, SHI Bao-Xin

Scientia Agricultura Sinica. 2012, 45(12): 2491-2501. doi:10.3864/j.issn.0578-1752.2012.12.019

Abstract ( 667 )

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【Objective】 The objective of the experiment is to express and purify E. granulosus (Eg) heat shock protein 70 (EgHsp70) in E. coli and prepare the antibody against E. granulosus. 【Methods】 EgHsp70 gene was amplified by PCR and cloned into prokaryotic expression vector pMAL-p2x, and the recombinant plasmid was transformed into E. coil BL-21. The soluble expression conditions of fusion protein were optimized by induction with different concentrations, of IPTG different temperatures and cultivation times. The expressed fusion protein was purified by Mal-tag Magnetic Beads. To prepare the anti-serum, New Zealand white rabbits were immunized with purified EgHsp70 protein via hypodermic and volar. Western blot was used to determine the serum’s specificity against EgHsp70 and native proteins. The serum titers were analyzed by ELISA. 【Results】 Full-length of EgHsp70 gene had an open reading frame of 765 bps encoding a protein mass of 68.6 kD. Restriction endonuclease analysis and DNA sequencing showed that EgHsp70 was cloned into the plasmid pMAL-p2x. Based on the optimization experiments, it was concluded that the best soluble expression conditions for the EgHsp70 protein are using 0.3 mmol ?L-1 IPTG when bacterial cells growing to OD600 0.6 and induced for 4 h at 30℃. ELISA and Western blotting showed that the titers of the anti-serum were above 1﹕256 000, and the anti-serum could specifically bind with EgHsp70 protein and native proteins. 【Conclusion】 The EgHsp70 fusion protein was obtained by expressing in E.coli and purifying, and the antibody against EgHsp70 was prepared with the fusion protein immunized New Zealand white rabbits. This work will provide an antigen and detection antibody for further study on the EgHsp70 function. The protein is immunogenic and can be a vaccine candidate against Echinococcus infection.

Cloning of a Plasma Membrane Protein Gene TaPM19-1 and Its Response to Abiotic Stresses in Wheat

LI Yong-Chun, ZHANG Chun-Yan, ZHANG Ning, MENG Fan-Rong, REN Jiang-Ping, NIU Hong-Bin, WANG Xiang, YIN Jun

Scientia Agricultura Sinica. 2012, 45(12): 2502-2509. doi:10.3864/j.issn.0578-1752.2012.12.020

Abstract ( 823 )

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【Objective】 The characteristics of a plasma membrane protein gene TaPM19-1 and its response to abiotic stresses in wheat were studied, which will provide an insight into its biological roles involved in the molecular mechanisms of abiotic-sterss response in wheat. 【Method】 RACE technology was used in full-length cDNA cloning and proper bioinformatics software was applied for characterizing the cloned gene and its deduced protein. Semi-quantitative RT-PCR was performed to study the expression patterns of TaPM19-1 under abiotic stresses. 【Result】 The full-length cDNA of TaPM19-1 is 1 090 bp and no introns were included. TaPM19-1 consists of 182 amino acids with a molecular weight of 19.02 kD, and an typical AWPM19 conserved domain was found in it. Based on the amino acid sequences, 16 AWPM19-like proteins of different plant species were sorted into 3 categories, TaPM19-1 and 3 others, 2 AWMP19-like proteins of Hordeum vulgare and 1 of Brachypodium distachyon, were highly similar and included in the third category. The structural prediction of TaPM19-1 revealed that 4 transmembrane regions with alpha helixes could be formed, the N-terminal (including a signal peptide consists of 27 amino acids) was located inside the membrane, while the C-terminus (about 40 amino acids) located inside. The RT-PCR analysis showed that the expression of TaPM19-1 was not detected in all tissues except in later period of developing seeds. The expression of TaPM19-1 was greatly induced by ABA in roots of two detected wheat cultivars, while its expression in leaves was very low. Under the water stress, the gene was immediately and highly induced both in roots and leaves. The expression of TaPM19-1 can be induced by salt- and heat-stress in Luohan 2, while not induced in Chinese Spring. Under lower temperature treatment, no expression of TaPM19-1 was detected in both wheat varieties. 【Conclusion】 The full-length cDNA of TaPM19-1 was obtained and some typical transmembrane structural features were found in its deduced protein. The expression of TaPM19-1 can be induced by plant hormone ABA. TaPM19-1 can also be induced by drought-, salt- and heat-stress in Luohan 2, while not response to salt- and heat-stress in Chinese Spring. The results suggested that TaPM10-1 might have different transcriptional regulating mechanisms in Luohan 2 and Chinese Spring.

Effects of Silicon on the Physiological and Biochemical Characteristics of Roots of Rice Seedlings Under Water Stress

MING Dong-Feng, YUAN Hong-Mei, WANG Yu-Hai, GONG Hai-Jun, ZHOU Wei-Jun

Scientia Agricultura Sinica. 2012, 45(12): 2510-2519. doi:10.3864/j.issn.0578-1752.2012.12.021

Abstract ( 982 )

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【Objective】 In order to clarify the mechanism of silicon (Si) in enhancing the resistance to water stress, the effects of Si on the physiological and biochemical characteristics of the roots of rice seedlings were investigated under water stress. 【Method】 The effects of exogenous Si on the physiological and biochemical parameters of roots of rice [(Oryza sativa ssp. (keng) Ting cv. Xiushui 11) and Brazilian upland rice (O. sativa cv. IAPAR 9)] were investigated under water stress induced by polyethylene glycol (PEG) in hydroponic conditions. 【Result】 Exogenous Si could restrain excessive respiration, and increase the dry matter weight and relative water content of the PEG-stressed rice roots. On the 8th day after PEG treatment, the malondialdehyde (MDA) content in the roots of both Si-treated rice cultivars was decreased by 23% and 21%, and the relative electrolyte leakage was decreased by 39% and 38%, respectively, as compared to those of PEG treatment only. Consequently, the plasma membrane stability of the stressed roots was enhanced by Si application. In addition, exogenous Si also increased the root antioxidant defense capacity, slowed down the degradation of abscisic acid (ABA) in rice roots under PEG stress. 【Conclusion】 Silicon application could enhance the resistance of rice roots to water deficit stress by preventing the rapid decline of physiological and biochemical activities in roots.

Effect on Soil Infiltration of Water and Soil Loss Made by Earthquake in Wenchuan Area

XU Xiao-Jun, HE Bing-Hui, HU Heng, XIONG Ming-Biao, YANG Wen-Bing, LI Zhen-Lin

Scientia Agricultura Sinica. 2012, 45(12): 2520-2529. doi:10.3864/j.issn.0578-1752.2012.12.022

Abstract ( 682 )

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【Objective】This paper discussed the influence on soil infiltration caused by soil and water loss in wenchuan earthquake area．【Method】On the basis of cutting ring method and stratified sampling，we studied the soil infiltration influenced by soil and water loss under four different kinds of sampling plots in caopo river watershed after earthquake．【Result】Under the impact of soil and water loss, soil bulk density, soil porosity condition and moisture holding capacity of the soil of bare land、naturally restored land and cultivated-after-earthquake land were poorer than control (the plots where weren’t struck by the earthquake). Soil beginning infiltration rate, steady infiltration rate, average infiltration rate and infiltration amount in 75 min presented control＞cultivated-after-earthquake land＞naturally restored land＞bare land. Pearson correlation analysis result showed that soil permeability showed a highly significant (P＜0.01) or significant (P＜0.05) positive linear correlation with non-capillary porosity and total porosity, a highly significant (P＜0.01) or significant (P＜0.05) negative linear correlation with bulk density, but no significant linear correlation with capillary porosity. Using the comprehensive judgment value (F) evaluated soil infiltration capability quality of different types of sample soil which recovered after earthquake, The result was presented as follows: control (1.2569)＞cultivated-after-earthquake (-0.2252)＞naturally restored land (-0.4578)＞bare land(-0.5738). Regression analysis of model simulation indicated that general empirical model and Horton model were the optimal to describe the soil infiltration while Kostiakov model less, Philip model the least.【Conclusion】Soil and water loss influenced soil water infiltration. soil water infiltration capacity of control was the best on Wenchuan earthquake zone while soil bulk density was about 1 g•cm-3, soil total porosity about 50% , non-capillary porosity 20%-40%. Restoring naturally and planting vegetation which resulted in decrease in soil bulk density, increase in soil total porosity and non-capillary porosity, strengthening of the water holding capacity and improvement of the permeability can reduce the surface runoff and prevent water and soil loss effectively.

Characteristics of Water Transportation for Apple Trees Submitted by Partial Root-Zone Irrigation

WEI Qin-Ping, LIU Song-Zhong, ZHANG Qiang, WANG Xiao-Wei, LIU Jun

Scientia Agricultura Sinica. 2012, 45(12): 2530-2536. doi:10.3864/j.issn.0578-1752.2012.12.023

Abstract ( 656 )

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【Objective】Water transportation between root and shoot, and root to root und partial root-zone irrigation was investigated in this study.【Method】Potted three-year old ‘Royal Gala’ apple trees were used to investigate characteristics of water transportation and distribution in root and organs of shoot, as well as water transportation in root of irrigated root-zones and drought root-zones at different time points after partial root-zone irrigated by deuterated water (HDO). 【Result】The highest abundance of HDO for treatment in 1/4 root-zone irrigation was firstly found in the root, and then in different organs of shoot, however, the highest HDO abundance for treatment of 2/4 root-zone irrigation was simultaneously found in the root and shoot, but the time was postponed in comparison to treatment of 1/4 root-zone irrigation. HDO abundance in root for 288 hours was higher than that in organs of shoot all the time. After 1/4 and 2/4 root-zones were irrigated by HDO for 2 hours, the percentages of HDO abundance in the root demonstrated a sequence of absorbing root＜2-5 mm root ＜2 mm root＜ roots with a diameter more than 5 mm, and the highest HDO abundance for organs of shoot was found in leaves and trunk. 【Conclusion】The results showed that water absorbed by root firstly satisfy its own demand, and then were transported to shoot when water supply was insufficient, otherwise, water was transported to root and shoot at the same time. It is preliminarily assumed that water transportation from irrigated root-zones to drought root-zones is realized mainly in turn by roots of diameter more than 5 mm, roots between 2-5 mm, roots with a diameter less than 2 mm and the absorbing roots.

Genetic Diversity of Saccharomyces cerevisiae Strains Revealed by Microsatellite Sequence Polymorphism

FENG Min, WANG Chun-Xiao, LIU Yan-Lin

Scientia Agricultura Sinica. 2012, 45(12): 2537-2543. doi:10.3864/j.issn.0578-1752.2012.12.024

Abstract ( 743 )

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【Objective】A total of 48 Saccharomyces cerevisiae strains from Xinjiang and Ningxia regions were typed by 4 microsatellite markers, and the genetic relations among the strains were also analyzed.【Method】A total of 48 Saccharomyces cerevisiae strains were discriminated for polymorphism at the 4 selected loci: SCAAT1, SCYOR267c, C11, and YPL009c.【Result】A total of 87 alleles, which generated 39 genotypes, were found. The polymorphism information contents (PIC) of all strains at 4 loci were 0.8593-0.9115, suggesting that the 4 SSR loci were hypervariable. The heterozygosity expected and heterozygosity observed were 0.8803-0.9268 and 0.8333-0.9792, respectively.【Conclusion】The results showed the diversity of Saccharomyces cerevisiae strains in Ningxia and Xinjiang regions.

Crop Insurance Premium Rating Based on Yield Simulation Models

YE Tao, NIE Jian-Liang, WU Bin-Xia, LI Man, SHI Pei-Jun

Scientia Agricultura Sinica. 2012, 45(12): 2544-2551. doi:10.3864/j.issn.0578-1752.2012.12.025

Abstract ( 768 )

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In recent years, crop insurance in China grows rapidly, but it still lacks actuarial support. The yield simulation model is one of the most widely employed models used in crop insurance premium rating, and is tailored for multi-peril yield insurance lines. It will promote crop insurance rating research and practice in China to comprehensively introduce the model. This article summarized the major issues that induce uncertainty and problems in accuracy in the yield simulation model, and provided discussions on its future development on the basis of a comprehensive review. It was found that detrending and distribution fitting are the two major uncertain factors. The problem that has not been well solved by the model is the aggregation of spatially-correlated risks. It was suggested that detrending analysis should pay enough attention to information beyond the yield data and emphasize on trend verification. Empirical models used for distribution fitting should be crop and region specific. The most urgent development for the yield simulation model is incorporating spatial elements and developing integrated spatial-temporal yield simulation model to cope with spatial correlation of individual risks. All of these require further interdisciplinary efforts from geography, agriculture, disaster and risk, and actuary, etc., to improve the capability of classic yield simulation model.

Emergy Analysis of Agro-ecosystem of Resource-based City in Vulnerable Eco-regions ——A Case of Yulin City

LI Jun-Li, CAO Ming-Ming

Scientia Agricultura Sinica. 2012, 45(12): 2552-2560. doi:10.3864/j.issn.0578-1752.2012.12.026

Abstract ( 760 )

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【Objective】 The development state and major sustainable development obstacle of ago-ecosystem about resource-based city in vulnerable eco-regions were studied. 【Method】 The input and output state and comprehensive development level of ago-ecosystem in Yulin city, from 2000 to 2008 were analyzed by using the method of emergy analysis.【Result】The results of emergy input and output showed that the main emergy input of agro-ecosystem of Yulin city was unpaid emergy. The industrial assistant emergy of the total emergy input ratio in 2008 was only 1/4 of the national average, while the labor emergy accounted for up to 68% of renewable organic emergy; the ago-ecosystem of Yulin city was still in the stage of traditional agriculture and depended on manpower and environmental resources. The results of comprehensive evaluation showed that the development potential in Yulin City is high and it has strong sustainable ability of ago-ecosystem. The development state of the natural ago-ecosystem is relatively superior. The development state of the economic ago-ecosystem is low, but the development potential is great. The development state of the social ago-ecosystem was improved, but the production efficiency of rural labor was low. In 2008, the production superiority degree index was 0.71 and the competitive industry (livestock) was obvious; the system stability degree index was only 0.49 and the stability of itself needs to be enhanced; the emergy sustainability index was 2.76 and the ago-ecosystem was a dynamic system. 【Conclusion】Some measures should be taken to make the ago-ecosystem input and output emergy to a higher level and make the traditional extensive mode to modern scientific technology, highly intensive and high efficiency, such as improving renewable resources use efficiency, optimizing system structure, increasing the investment of agricultural science and technology assistant emergy.

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