Loading...

Table of Content

    20 May 2014, Volume 47 Issue 10
    CROP GENETICS & BREEDING·GERMPLASM RESOURCES·MOLECULAR GENETICS
    Polymorphism of TaSnRK2.10 and Its Association with Yield-Related Traits in Wheat
    WANG Qian-1, 2 , MAO Xin-Guo-2, CHANG Xiao-Ping-2, JIA Ji-Zeng-2, LIU Hui-Min-1, JING Rui-Lian-2
    Scientia Agricultura Sinica. 2014, 47(10):  1865-1877.  doi:10.3864/j.issn.0578-1752.2014.10.001
    Abstract ( 545 )   HTML ( 2 )   PDF (743KB) ( 784 )   Save
    References | Related Articles | Metrics
    【Objective】 The sucrose non-fermenting protein kinase (SnRK) is a kind of Ser/Thr protein kinase found widely in plants and participates a variety of transductions in signaling pathway in plants. TaSnRK2.10 is an important SnRK2 member involved in response to various abiotic stresses in wheat (Triticum aestivum L.). The objective of this study is to detect the single nucleotide polymorphism (SNP) of TaSnRK2.10, develop and map its functional markers, analyze the relationship between its haplotypes and phenotypic traits, and provide a basis for the genetic improvement and germplasm enhancement by molecular marker assisted selection in wheat. 【Method】 Thirty hexaploid wheat accessions with high polymorphism and their diploid and tetraploid wild relative species were selected to detect the nucleotide polymorphism in TaSnRK2.10-A gene by sequencing. A set of Chinese Spring nulli-tetrasomic lines and the recombinant inbred lines (RIL) derived from a cross of “Yanzhan 1 × Neixiang 188” were used to map TaSnRK2.10-A on chromosome. Based on the polymorphism in the sequence of TaSnRK2.10-A molecular markers were developed. The relevance between TaSnRK2.10-A haplotypes and phenotypic traits was analyzed using a natural population consisted of 262 historical wheat accessions. 【Result】 The sequences of TaSnRK2.10 on genomes A and D were cloned, named as TaSnRK2.10-A and TaSnRK2.10-D. There was no SNP detected in the sequence of TaSnRK2.10-D, but the full length of TaSnRK2.10-A was 4 688 bp with 15 SNPs and 2 InDels. Among them, 8 SNPs were identified in the promoter region, 2 SNPs in 5′-UTR region, and 5 SNPs in the coding region with 2 SNPs in exon. One of SNPs in exon was non-synonymous mutation. Four markers were developed. They were PM1 and PM2 for the promoter region, GM1 and GM2 for the coding region. TaSnRK2.10-A was mapped in the intervals between markers Xwpt7001 and WMC48 on chromosome 4A, with 5.1 cM and 25.7 cM from the flanking markers. In the natural populations consisted of 262 accessions, four haplotypes of TaSnRK2.10-A were detected by four markers that were associated with 1000-grain weight, spike per plant and spikelet per spike. The HapⅡand HapⅢ of TaSnRK2.10-A are considered as potential superior haplotypes for the improvement of 1000-grain weight. The base C at the site of 4 184 bp is a superior allele for high 1000-grain weight. 【Conclusion】 The present research mapped TaSnRK2.10-A on the chromosome 4A. The HapⅡand HapⅢ of TaSnRK2.10-A are considered as potential superior haplotypes for the improvement of 1000-grain weight, while HapⅣ is a potential superior haplotype for spike per plant. The cytosine (C) at the position of 4 184 bp is the superior allele.
    Study on the Differential Genes Expression in Maize Embryo Treated by a Controlled Deterioration Treatment
    YANG Wei-Fei, ZHANG Jing-Long, 吕Wei-Zeng , CAO Guang-Can, CHEN Jun-Ying
    Scientia Agricultura Sinica. 2014, 47(10):  1878-1893.  doi:10.3864/j.issn.0578-1752.2014.10.002
    Abstract ( 436 )   HTML ( 2 )   PDF (788KB) ( 843 )   Save
    References | Related Articles | Metrics
    【Objective】 In this work, digital gene expression tag profiling (DGE) was employed to investigate the differentially expressed genes (DEGs) in the embryo of maize seeds treated by a controlled deterioration treatment (CDT) to provide a basis for a better understanding of essential molecular mechanism underlying seed deterioration. 【Method】 In this study, maize (Zea mays L.) cultivar (zhengdan 958) seeds were used as a model and treated by CDT (45℃, 100% relative humidity) for 72 h (T), untreated seeds were used as control (CK). DGE was performed and the high-quality sequences were mapped to the reference genome and maize genes database to obtain the expression genes. The expression level of each gene was calculated by RPKM method. A combination of FDR<0.001 and the absolute value of |log2 ratio (T/CK)|≥1 was used as the threshold to determine the significance of gene expression difference. Finally, GO and pathway enrichment analysis were used to identify the significantly enriched function classification and metabolic pathways in DEGs.【Result】About 3 2000 mRNAs were detected in dry maize embryos (CK). A total of 4 713 DEGs, including 2 874 up-regulated and 1 839 down-regulated, were identified under CDT for 72 h. GO enrichment analysis revealed that the DEGs involved in three GO categories, i.e., cellular component, molecular function and biological process. The proteins coded by these genes were distributed on organelle/membrane in cells and participated in some metabolic processes, signaling transduction, response to stimulus and death process, etc. They would have binding, catalytic activity, and antioxidant activity, etc. There were 2 470 annotated DEGs that participated in 288 KEGG pathways in which 16 pathways were significantly enriched. Among these pathways, there were 113 genes involved in energy metabolism, i.e, 59 genes in glycolysis /gluconeogenesis, 50 genes in pyruvate metabolism, and 31 genes in pentose phosphate metabolism, respectively. The genes encoding enolase and glyceraldehyde 3-phosphate dehydrogenase in glycolysis /gluconeogenesis,pyruvate kinase in pyruvate metabolism,and alpha-L-fucosidase in pentose phosphate metabolism were up-regulated at highest levels. There were 25 genes that regulate the metabolism of NADH (9 up-regulated and 16 down-regulated genes) and 10 genes regulate the metabolism of NADPH (4 up-regulated and 6 down-regulated genes) were detected. They may regulate reactive oxygen species (ROS) production and accumulation. 【Conclusion】DGE provided an innovative and powerful tool for investigating the molecular mechanism of seed deterioration or vigor loss during aging. CDT could affect DEGs expression in dry maize embryos and then energy metabolism in cells. They would inhibit glycolytic pathway and promote ROS production and accumulation, then, accelerate cells aging or death in seed embryos, and ultimately lead to seed deterioration and vigor loss. DEGs might play a critical role in the process.
    The Genome-Wide Analysis of MicroRNAs and Their Target Genes in Nicotiana tomentosiformis and Nicotiana sylvestris
    LI Ling-1, 2 , ZHANG Lei-3, CHAO Jiang-Tao-1, GONG Da-Ping-1, LI Feng-Xia-1, WANG Qian-1, DING An-Ming-1, 2 , CHEN Ya-Qiong-1, 2 , SUN Ting-Ting-1, 2 , SUN Yu-He-1
    Scientia Agricultura Sinica. 2014, 47(10):  1894-1903.  doi:10.3864/j.issn.0578-1752.2014.10.003
    Abstract ( 440 )   HTML ( 1 )   PDF (630KB) ( 696 )   Save
    References | Related Articles | Metrics
    【Objective】The objective of this study is to fill the gaps in miRNA-related fields of Nicotiana tomentosiformis and N. sylvestris research as quickly as possible, and to reveal the growth and development regulation mechanism in N. tobacum, 【Method】the microRNAs and their target genes of N. tomentosiformis and Nicotiana sylvestris were genome-wide predicted and analyzed. miRNAs were predicted by the method of homologous alignment and secondary structure characteristics of pre-miRNA: reference sequence in sequence alignment of N. tomentosiformis and N. sylvestris were allowed 1-2 mispairings; secondary structure of miRNA was classic stem loop structure, maximum value of MEF was -25, minimum value of MEFI was 0.85, the predicted miRNA and the same family miRNA located on the same arm of hairpin structure; E-values of encoding protein sequence less than or equal to 1e-6 were eliminated. 【Result】 A total 162 miRNAs belonging to 39 families were identified in N. tomentosiformis, including 14 pairs of sense and antisense strand miRNAs and 5 gene clusters. A total 169 miRNAs belonging to 40 families were identified in N. sylvestris, including 13 pairs of sense and antisense strand miRNAs and 3 gene clusters. In high degree of miRNA conservative families, members of the distribution and membership were near in 2 wild tobaccos. While in a relatively low degree of conservative families, members of 2 wild tobaccos differed obviously. Nine families like miR5021, miR5203 and so on, got members in N. tomentosiformis. Ten families like miR1446, miR1509 and so on, got members in N. sylvestris. Antisense miRNA and their sense partners from 2 wild tobaccos differed from 1 to 4 bases, these differences location presented preferences in different families, and the preferences were similar in 2 wild tobaccos: 9th, 12th, 13th base in miR164 family, 1st, 21st base in miR172 family, 2nd, 17th base in miR396 family, 15th, 20th base in miR399 family. Gene cluster of 2 wild tobaccos consisted of miR156 family and miR169 family, distance of pre-clusters was less than 350nt. miR6019/miR6020 gene clusters were found in N. tomentosiformis for the first time. Unigene of N. tabacum was used as target genes. In N. tomentosiformis, 749 target genes of 122 miRNAs were identified. With duplicate genes eliminated, 206 non-redundant target genes were identified, in which, 89 target genes (43%) got GO annotations. In N. sylvestris, 117 target genes of 650 miRNAs were identified. With duplicate genes eliminated, 169 non-redundant target genes were identified, in which, 78 target genes (46%) got GO annotations. In terms of molecular function, most of the target genes have binding activity. In the process of biology, target genes mainly involved in the development process, reproductive process, multicellular organ development process, stress response and so on. 【Conclusion】 In N. sylvestris, there are more target genes control development and multicellular development, while in N. tomentosiformis, there are more target genes control stimulus and press reply.
    TILLAGE & CULTIVATION·PHYSIOLOGY & BIOCHEMISTRY·AGRICULTURE INFORMATION TECHNOLOGY
    Impacts of Climate Warming on Growth and Yield of Spring Maize in Recent 20 Years in Northeast China
    CHEN Qun, GENG Ting, HOU Wen-Jia, CHEN Chang-Qing
    Scientia Agricultura Sinica. 2014, 47(10):  1904-1916.  doi:10.3864/j.issn.0578-1752.2014.10.004
    Abstract ( 537 )   HTML ( 2 )   PDF (617KB) ( 1155 )   Save
    References | Related Articles | Metrics
    【Objective】In order to seek the impacts of climate warming on growth process and yield of spring maize in recent 20 years in Northeast China, a study was conducted for providing a theoretical basis for food security.【Method】Three provinces (Heilongjiang, Jilin and Liaoning province) in Northeast China were selected for conducting regional research. Making use of the meteorological observation data and the long-term observation data of spring maize in recent 20 years in Northeast China, the relationships between climate factors (temperature and precipitation) and growth process and historical production data during growing season were analyzed by correlation and regression analysis and other statistical methods.【Result】It was found that the diurnal maximum temperature, minimum temperature and average temperature in Northeast China during spring maize growth season in 1989-2009 were rising significantly. Climate trend rates were 0.050, 0.045 and 0.044 ℃?a-1. During spring maize growth warming amplitude during the daytime was larger than the night. No significant change in the precipitation was found. During 20 years, the change tendency of spring maize average sowing date was 0.10 d in advance every year in experiment stations of Heilongjiang province, but the change tendencies were postponed in experiment stations of Jilin and Liaoning provinces, respectively, 0.18 and 0.21 d per year. The change tendencies of spring maize average maturity date were postponed in experiment stations of Heilongjiang, Liaoning and Jilin provinces, respectively, 0.39, 0.35 and 0.55 d per year. The change tendencies of spring maize average total growth days in Heilongjiang, Jilin and Liaoning provinces were an annual increase of 0.49, 0.17 and 0.34 d, respectively. The amplitude of the delayed maturity date was larger than the delayed sowing date, eventually resulting in increased number of spring maize growth days. The national varieties data and meteorological data correlation analysis in 1991-2006 showed that the rise of the diurnal maximum temperature (Tmax) in Heilongjiang extended national varieties growth period. The correlation between the state-approved varieties growth period and the diurnal maximum temperature (Tmax), minimum temperature (Tmin), average temperature (Tavg) in Jilin and Liaoning provinces showed a positive correlation. Analysis of the relationship between the growth period of the state-approved varieties and experiment station varieties by using T test showed that the growth days of them had a consistent increasing trend in Heilongjiang and Liaoning provinces, and the increasing trend had no significant difference. By adopting linear partial regression test method the importance of varieties and climatic factors on spring maize growth period was analyzed and the results showed that the extension of varieties growth period was the main factor causing experiment station varieties growth period prolonged. The average yield of spring maize showed an increasing trend, and the ascending order of the trend was Liaoning, Jilin and Heilongjiang provinces in recent 20 years. The farther north the yield increasing trend was greater, and the yield increase was more obvious. Panel data analysis showed that changes of the Tavg, Tmax and Tmin affected the yield of spring maize in prefecture-level city of Northeast China in 1989-2009. When the temperature rose, the yield in northeast significantly increased, especially in the Sanjiang plain area of the eastern Heilongjiang province, but the yield in southwest cities was obvious reduced in Northeast China.【Conclusion】Above evidences indicate that spring maize production is affected by climate warming in Northeast China. Spring maize varieties are gradually adapted to climate warming. Varieties improvement and sowing date adjustment for adapting climate warming can improve the yield of spring maize.
    Effect of Ridge Film Mulching Technique and Furrow Seeding of Spring Corn on Water Use and Yield in Semi-Arid Region in Liaoxi Area
    XIAO Ji-Bing-1, SUN Zhan-Xiang-2, JIANG Chun-Guang-1, LIU Zhi-1, ZHENG Jia-Ming-2, FENG Liang-Shan-2
    Scientia Agricultura Sinica. 2014, 47(10):  1917-1928.  doi:10.3864/j.issn.0578-1752.2014.10.005
    Abstract ( 478 )   HTML ( 1 )   PDF (720KB) ( 720 )   Save
    References | Related Articles | Metrics
    【Objective】 Spring corn was the staple crop in Liaoxi area, but the shortage of precipitation and the big precipitation variation and its uneven distribution of time and space are the key limiting factor in the area. The limited rainfall can not meet the demand of stable and high yield of spring corn. Ridge film mulching and furrow seeding can collect natural precipitation effectively and improve rainfall resource availability. The purpose of this study is to make full use of the limited natural rainfall, improve water use efficiency of dry farming area and promote high and stable yield of spring corn.【Method】 Micro- rainwater-collecting planting mode by ridge film mulching and furrow seeding for spring corn was carried out for the sake of studying the effect of different planting patterns on soil water, yield and water use efficiency in 2007-2013. Four treatments were made in this experiment: ridge film mulching and furrow seeding (furrow was uncovered, T1), ridge film mulching and furrow straw mulching (T2), ridge and furrow film mulching (T3) and the traditional planting (CK). The experiment was designed by random grouping and repeated three times. The traditional planting was sowing in furrows, line spacing was 50 cm. Ridges and furrows of ridge film mulching and furrow seeding were in opposite arrangement, furrow width was 80 cm and ridge width was 40 cm, ridge height was 15 cm. The ridge was the rain collecting area. The furrow was the planting area and two lines of corn were planted. Planting density of different treatments was 52 500 plants/hm2. Seed manure was diammonium phosphate(375 kg•hm-2, N 18%, P2O5 46%)and topdressing was urea (375 kg•hm-2, N 46%).【Result】 The results showed that the ridge film mulching and furrow seeding could collect natural rainwater effectively, raise emergence rate of spring corn by 13.0% and 14.9% and emergence time was 1-2 d early in 2009-2010. Under the condition of no effective rainfall for a long time in early days, the order of increase of soil water storage in different treatments was T2>T1>CK>T3 after an effective rainfall. T1 and T2 enhanced water infiltration depth to 60㎝ in planting area compared with the control, which was 40 cm. The runoff efficiency was 61% and the rate of increase of soil moisture storage of T1 and T2 was 72% and 88%. The average of soil water of T1, T2, T3 and the control was 135.27 mm, 140.93 mm, 127.85 mm and 118.98 mm during growth stages of spring corn, increased by 13.69%, 18.45% and 7.46%, respectively, compared with the control. The yield of T1-T3 increased by 24.31%-32.58%, 9.95%-17.81%, 32.12%-37.16%, 16.58%-27.96%, 2.50%-9.40%, 10.85%-29.33% and 4.14%-17.95% in 2007-2013, the average production of T1, T2 and T3 increased by 14.52%, 20.01% and 23.44% compared with the control. The water use efficiency of T1-T3 increased by 24.66%-36.07%, 14.12%-23.73%, 38.34%-53.89%, 29.07%-35.68%, 1.20%-19.60% and 9.02%-32.55%, the average of water use efficiency of T1, T2 and T3 increased by 20.39%, 27.94% and 28.02% compared with the control. It was also found that the effect of increase of yield and water use efficiency was significant under lower rainfall.【Conclusion】 The effect of Micro- rainwater-collecting planting mode by ridge film mulching and furrow seeding in dry farmland on rainwater harvesting, water storage and soil moisture conservation was definite after 7 years of study in semi-arid region in Liaoxi area. The technique could mitigate the negative impact of drought on spring sowing and seedlings growth in spring and enrich the theoretical basis of the rain-harvesting agriculture of dry farming in the area. By application and dissemination of the technique, it could improve rainfall resources utilization and water use efficiency and promote stable and high yield of spring corn and healthy and sustainable development of dry farming in the area. The study will provide important references for development of the rain-harvesting agriculture of dry farming in the north of China.
    Effect of Soil Inorganic N Concentrations on the Nodulation, N2 Fixation and Yield in Soybean in a Pot Experiment
    YAN Jun, HAN Xiao-Zeng
    Scientia Agricultura Sinica. 2014, 47(10):  1929-1938.  doi:10.3864/j.issn.0578-1752.2014.10.006
    Abstract ( 432 )   HTML ( 2 )   PDF (526KB) ( 547 )   Save
    References | Related Articles | Metrics
    【Objective】 The response of N2 fixation and yield to N fertilizer, even with same N application rate, gives varying and contradicting results. The contradicting results depend on the perception of the system of soybean nitrogen fixation and root to the soil inorganic N concentration. The nodulation, fixation and yield of soybean with different soil inorganic N concentrations were studied to find the reasonable soil inorganic N concentration for promoting soybean yield, nodulation and fixation. i.e. to master the quantified relationship between soil inorganic N concentration, nodulation and fixation. Then it will have a significant theory and production meaning for adjusting N application rate, timing, and forecasting the effect of N fertilizer on the fixation and yield. 【Method】A pot experiment was conducted to study the effects of different soil inorganic nitrogen concentrations, which derived from total fertilizer N (as urea) applied at vegetative stage (V2), at early blooming stage (R1), at early podding stage (R3) and at grain filling stage (R5), on the ability of N2 fixation and yield, by measuring the nodule number, biomass and nitrogenase activity and yield components. Through the research, the response of soybean nodulation and yield to soil inorganic N concentration cleared, and thus mastering the quantity relationship between soil inorganic N concentration and N application, nodulation and yield, and then providing a theoretical basis for agriculture production and scientific research. 【Result】 The nodule number, biomass and nitrogenase activity of soybean reached peak at R4 stage, while decreased at R6 stage, and the nodule number, biomass and nitrogenase activity were in order of V2>R5>R3>R1. The nodule biomass decreased by 15%, 18%, 17% and 32% compared to that of CK. The nodule number decreased by 13%, 18%, 19% and 20%. The nitrogenase activity decreased by 19%, 22%, 23% and 32%. Meanwhile, there were significant negative linear correlations between nodule number, biomass and nitrogenase activity at R6 stage and the concentration of soil inorganic nitrogen. Moreover, The trends of dry matter accumulation and yield were expressed as an order of R1>R3>V2>R5. Except the treatments at R5 had no significant correlations with the treatment of CK, the other treatments had a significant promoted effect on dry matter accumulation and yield. The treatment of N3 had the highest dry matter accumulation, plant height, pod number, pod dry weight and yield than the other treatments at different growth stages. The soil inorganic N concentration at V2 stage had a significant effect on nodulation and the ability of nitrogen fixation, and that at R1 stage had a significant effect on growth and yield. There were different threshold values of soil inorganic nitrogen concentration at different growth stages. The soil inorganic N concentration should be reached 135.8 mg•kg -1 at V2 stage, 58-91 mg•kg -1 at R1 stage; 29.4-62.8 mg•kg -1 at R3 stage; 102.3 mg•kg -1 at R5 stage to promote soybean nitrogen fixation and yield. 【Conclusion】 The response of N2 fixation and yield to N fertilizer mainly depended on the soil inorganic N concentration which was affected by N fertilizer application rate and timing. The soil inorganic N concentration was adjusted by agriculture production and scientific experiment. The nodule number, biomass and nitrogenase activity were significantly affected by the soil inorganic N concentration at V2 stage than that at the other growth stages, while the biomass and yield were significantly affected by the soil inorganic N concentration at R1 stage than that at other growth stages.
    PLANT PROTECTION
    Cloning and Expression Analysis of the Endo Polygalacturonases Gene endoPGs in Rhizoctonia solani Causing Tobacco Target Spot
    ZHAO Yan-Qin-1, 2 , WU Yuan-Hua-1, ZHAO Xiu-Xiang-1, CHEN Jian-Guang-1, FU Ying-1, AN Meng-Nan-1
    Scientia Agricultura Sinica. 2014, 47(10):  1939-1946.  doi:10.3864/j.issn.0578-1752.2014.10.007
    Abstract ( 397 )   HTML ( 2 )   PDF (715KB) ( 653 )   Save
    References | Related Articles | Metrics
    【Objective】 Endo polygalacturonases (endoPGs) is considered to be one of the important pathogenic factors. The objectives of this study are to clone and compare endoPGs from the strong pathogenic strain YC-9 and the weak pathogenic strain LF-2 from Rhizoctonia solani, analyze the sequence features, evolutionary relationships and expression characteristics of endoPG1 and endoPG2, and to provide a theoretical foundation for clarifying molecular mechanism of the pathogenicity. 【Method】 Degenerate primers were developed based on the sequence of different endoPGs from plant pathogens in GenBank, and partial cDNA fragments of the strains YC-9 and LF-2 were firstly acquired, then the full-length cDNA sequences were cloned through RACE techniques, and the conserved domains and sequence features of the genes were analyzed by bioinformatics’ methods. A phylogenetic tree was constructed using the MEGA 4.0 software, and the relative expression characters of endoPG1 and endoPG2 were also analyzed by real-time RT-PCR. 【Result】 Two endo polygalacturonases genes were cloned and named as endoPG1 and endoPG2. The genes possessed the conserved domains of PLNO3003 gene superfamily. The open reading frame (ORF) of the full length cDNA was 1 086 bp, encoding a protein of 361 amino acid residues. Differences between endoPG1 and endoPG2 were indicated by comparing the full-length cDNA sequences and transmembrane regions of prediction protein. The PLNO3003 subunit phylogenetic tree was constructed, which showed that the corresponding amino acid sequences of endoPGs from R. solani formed an independent branch, and that of endoPG1 and endoPG2 had the highest homology. Real-time RT-PCR demonstrated that the expression of endoPG1 and endoPG2 were more obviously up-regulated in hyphae of inoculated tobacco leaves than in hyphae of non-inoculated ones, and the expression quantity of endoPG1 was higher than that of endoPG2. 【Conclusion】 The full cDNA sequences of endoPG1 and endoPG2 were successfully cloned from tobacco target spot disease of R. solani, and both have conserved domains of PLNO3003 gene superfamily, and it has obviously differences between transmembrane regions of prediction protein of endoPG1 and endoPG2. Phylogenetic analysis showed that the corresponding amino acid sequences of endoPG1 and endoPG2 have a highest homology relationship. Finally the endoPG1 and endoPG2 gene expression can be obviously induced by interaction with tobacco and the strong and weak pathogenicity strains in YC-9 and LF-2 have obvious differences.
    Cloning and Expression Analysis of a Carboxylesterase Gene BdCAREB1 from Bactrocera dorsalis
    SHEN Guang-Mao, DOU Wei, WANG Jin-Jun
    Scientia Agricultura Sinica. 2014, 47(10):  1947-1955.  doi:10.3864/j.issn.0578-1752.2014.10.008
    Abstract ( 378 )   HTML ( 1 )   PDF (672KB) ( 553 )   Save
    References | Related Articles | Metrics
    【Objective】Based on the cloning of a carboxylesterase gene of Bactrocera dorsalis, the expressions of this gene among different developmental stages, tissues, and under insecticide stimulation were analyzed. Combined with previous data of enzyme activity assay and synergist analysis, the objectives of this study are to clarify the reaction of carboxylesterase when stimulated by β-cypermethrin, and lay a foundation for the future study of the mechanism that how carboxylesterase works in the detoxification of pyrethroid insecticides.【Method】From the transcriptome data of B. dorsalis, a partial sequence of carboxylesterase gene was screened out by using homologous blast, and the full sequence was cloned by using RACE technology. The ORF, deduced amino acid sequence, and molecular weight were predicted, and a phylogenetic tree with carboxylesterase genes from other insects was constructed by using maximum likelihood method to clarify its molecular characterization. RNA was extracted from different developmental stages and the midgut, Malpighian tubules, fat body, trachea of the 3rd instar larvae. Based on the reference evaluation, qPCR was used for the expression analysis of different developmental stages, tissues, and stimulated by insecticide. 【Result】A partial sequence of 1 028 bp was found in the transcriptome data. The results of 5′ and 3′ amplification were 1 073 and 625 bp, respectively. After sequence assemble and verification, the full-length of this gene was 1 872 bp, contained a complete ORF of 1 710 bp, and encoding a protein of 569 amino acids with a predicted molecular mass of 63.3 kD. It was named as BdCAREB1 and submitted to GenBank with an accession number of KF539980. The phylogenetic tree of BdCAREB1 showed high homology with carboxylesterase of Diptera. The qPCR result of different developmental stages of the 3rd instar larvae showed BdCAREB1 was highly expressed in the 3rd instar larvae, followed by the adults, and it was the lowest in the eggs. Among different tissues, the BdCAREB1 was highly expressed in fat body. The expressions between midgut and Malpighian tubules were quite the same, and in trachea, the expression was the lowest. After the insects were fed on a diet containing 0.33 μg?g-1 (insecticide/diet) β-cypermethrin, the expression of BdCAREB1 was significantly up-regulated in larvae and fat body. 【Conclusion】The specific expressions of BdCAREB1 were identified in different developmental stages and tissues, which were highly enriched in the larvae and fat body. It showed inducibility by the stimulation of β-cypermethrin. Combined with previous data of enzyme activity assay and synergist analysis, BdCAREB1 may be involved in the detoxification of β-cypermethrin.
    Molecular Characteristics and Functional Analysis of Three Cytochrome P450 genes in Locusta migratoria
    REN Xiao-Yu, YANG Mei-Ling, GAO Cui-E, ZHANG Jian-Zhen, MA EnBo
    Scientia Agricultura Sinica. 2014, 47(10):  1956-1965.  doi:10.3864/j.issn.0578-1752.2014.10.009
    Abstract ( 384 )   HTML ( 2 )   PDF (1113KB) ( 449 )   Save
    References | Related Articles | Metrics
    【Objective】The objective of this study is to elucidate the molecular function of the three cytochrome P450 genes of CYP4 family from the locust (Locusta migratoria). 【Method】According to the predicted P450 sequences from ESTs database of locust, the primers were designed, the full-length sequences of three novel genes were amplified and named CYP4C69, CYP4C73 and CYP4DH1 (GenBank accession numbers: KF857162, KF857163, KF857164), respectively. The mRNA expression levels of CYP4C69, CYP4C73 and CYP4DH1 were analyzed in different developmental stages and tissues of locusts by real-time quantitative PCR. The RNAi ef?ciency of dsCYP4C69, dsCYP4C73 and dsCYP4DH1 was evaluated by real-time quantitative PCR. The toxic effects of malathlon, chlorpyrlfos and deltamethrin on 2nd-instar nymphs were analyzed and the LC30 doses of the three insecticides were calculated by SPSS software. As CYP4C69, CYP4C73 and CYP4DH1 transcripts were signi?cantly repressed in locusts by RNAi, the susceptibility of the dsRNA injected locusts to different insecticides, such as malathion, chlorpyrifos and deltamethrin were assessed.【Result】The full-length cDNA sequences of CYP450 genes including CYP4C69, CYP4C73 and CYP4DH1 were obtained by RT-PCR. The cDNA sequences of CYP4C69, CYP4C73 and CYP4DH1 had open reading frames of 1 518, 1 521 and 1 512 nucleotides which encoded proteins of 506, 507 and 504 amino acid residues, respectively. Moreover, the expression level of CYP4C69 was higher in 5th-instar nymph than in the adult stage. However, CYP4C73 and CYP4DH1 expressed during the whole developmental stages and were relatively higher in 1st-, 4th- and 5th-instar nymphs and adult stage. The results of CYP4 genes expression from different tissues indicated that all of the three genes had a high expression level in gastric caeca, CYP4C69 and CYP4DH1 highly expressed in fat body. It was found that CYP4C69, CYP4C73 and CYP4DH1 transcripts were signi?cantly repressed in the locusts after dsRNA injection. The toxic effects of malathion, chlorpyrifos and deltamethrin on 2nd-instar nymphs indicated that the LC30 doses of the three insecticides were 59.438, 8.215, 0.759 μg•mL-1, respectively. The susceptibility of locusts to malathlon, chlorpyrlfos and deltamethrin showed that there was no marked difference between locusts’ injection of dsCYP4C69, dsCYP4C73, dsCYP4DH1 and dsGFP. 【Conclusion】The full-length cDNA sequences of CYP4C69, CYP4C73 and CYP4DH1 were obtained. And these genes could be silenced by dsCYP4C69, dsCYP4C73 and dsCYP4DH1. However, treatment with dsRNA of CYP4C73, CYP4C69, CYP4DH1 and dsGFP did not show signi?cant effects on the susceptibility of the locusts to malathion, chlorpyrifos and deltamethrin.
    SOIL & FERTILIZER·WATER-SAVING IRRIGATION·AGROECOLOGY & ENVIRONMENT
    Effects of Drip Fertigation with No-Tillage on Water Use Efficiency and Yield of Winter Wheat
    CHEN Jing-1, 2 , WANG Ying-Chun-1, LI Hu-1, WANG Li-Gang-1, QIU Jian-Jun-1, XIAO Bi-Lin-1
    Scientia Agricultura Sinica. 2014, 47(10):  1966-1975.  doi:10.3864/j.issn.0578-1752.2014.10.010
    Abstract ( 434 )   HTML ( 1 )   PDF (628KB) ( 869 )   Save
    References | Related Articles | Metrics
    【Objective】On the issues of drip irrigation water consumption and rational application of water and fertilization in the winter wheat belt region of Huang-Huai-Hai Plain, no-tillage fields were chosen as experimental sites located in Huantai, Shandong Province to carry out a systematic study on the effects of drip fertigation on soil moisture vertical migration, winter wheat grain yield and its components and water use efficiency (WUE).【Method】The study adopted the methods of irrigation recharge by measuring soil moisture and drip fertigation in the main growth period compared with conventional flood irrigation and fertilization treatment. Five drip irrigation level treatments including 65 mm (W1), 98mm (W2), 130 mm (W3), 195 mm (W4) and 260 mm (W5) were designed. The corresponding NPK ratio was set up at tillering stage, joining stage, booting stage, young flowering and filling stages of winter wheat under the 130mm of irrigation treatment level and 3 factors of NPK and 4 levels quadratic saturation D-optimization design were adopted for field experiment. The 4 levels of N, P, K were that “0 level” with 0, 0, 0, “1 level” with 94.5, 42.4 and 59.2 kg•hm-2, “2 level” with 189, 84.7 and 118.3 kg•hm-2, “3 level” with 270, 121 and 169 kg•hm-2.【Result】The results of experiment showed that the more drip irrigation amount is, the deeper soil moisture vertical migration will be, the soil moisture vertical migration of W1, W3 and W5 treatments moved to 60, 80 and 100 cm, and could get risk of water percolation while drip irrigation level achieved 260 mm. Soil moisture content of W1 treatment was obviously lower than others, 130 mm and above drip irrigation treatment made soil moisture content at 0-80 cm soil layers over 75%-80% of the field moisture capacity during the growth period. Compared with conventional flood irrigation and fertilization treatment, the drip fertigation significantly increased the effective panicles of winter wheat. The drip irrigation amount had a positive correlation with grain number per spike and a negative correlation with 1000-grain weight in different drip irrigation treatments. The grain yield was the highest when irrigation amount was 130 mm. Drip irrigation apparently increased water use efficiency (WUE) and with the highest of W3 treatment that was 2.28 kg•m-3. Experimental fitting results indicated that the optimal fertilizer amount of N, P2O5 and K2O in pilot area was 206.63, 86.72 and 88.07 kg•hm-2. 【Conclusion】It was concluded that the winter wheat in no-tillage fields by irrigation recharge by measuring soil moisture and drip fertigation significantly increased, WUE and yield by 57.46% and 21.13% in Huang-Huai-Hai Plain, respectively, compared with conventional treatment. The main reason was that the water moved to crop roots area after drip irrigation that could reduce the risk of water percolation and promote fertilizer-absorbing with water. The rational ratio of drip fertigation could totally make water saving by 51.85%, N, P, K fertilizer saving, respectively, by 23.47%, 28.33% and 47.89%.
    Effects of Different Winter Planting-Green Manure on the Grain Yield of Rice and Weed Community of Paddy Field
    CHEN Hong-Jun, HUANG Guo-Qin, YANG Bin-Juan, WANG Xiao-Wei
    Scientia Agricultura Sinica. 2014, 47(10):  1976-1984.  doi:10.3864/j.issn.0578-1752.2014.10.011
    Abstract ( 435 )   HTML ( 2 )   PDF (606KB) ( 749 )   Save
    References | Related Articles | Metrics
    【Objective】 This study aims at comprehensively evaluate different winter green manures on rice growth dynamics and paddy field weed community in southern rice region for further optimization of rice cropping patterns, and development of winter crop planting and development. 【Method】 From winter in 2011 in double cropping area in southern Jiangxi Agricultural University Science Park, winter green manure species including legumes, grasses, and cruciferous were selected to make comparison of milk vetch, rapeseed, ryegrass and mixed of green manure (vetch × rapeseed × fertile turnip) on rice yield and its components, dry matter production characteristics and weed communities. 【Result】 The results showed that the dry matter weight of population of rice in the treatment of MV-R-R(milk vetch-rice-rice) are all higher than others at tillering stage, booting stage, heading stage and maturity. The rate of increase was 14.46%, 10.99%, 11.83% and 7.23%, respectively. Compared with RG-R-R (ryegrass-rice-rice), RP-R-R (rapeseed-rice-rice), MS-R-R (mixed green manure-rice-rice), rice yield of MV-R-R was higher, increased by 6.61%, 3.29%, and 0.78%, respectively. Among the 4 different winter green manures, rice yield and yield components (effective panicles, grain number per panicle, seed-setting rate and 1000-grain weight) in treatment of MV-R-R were higher than other treatments. Dry matter accumulation in treatment of MV-R-R was higher than others in main growth periods of rice except for heading to maturity. Compared with RG-R-R, RP-R-R, MS-R-R (mixed green manure-rice-rice), the increasing rate were 11.38%-17.72%, 4.50%-28.00%, and 1.85%-35.25%, respectively. The dry matter accumulation in the periods of sowing to tillering and booting to heading were the biggest, which is the stage of rapid accumulation of substances. In the four treatments, dry matter accumulation at the two growth stages reached 70.43%, 60.50%, 69.87%, and 69.08% of that at maturity. While the proportion of dry matter accumulation from heading to maturity was the lowest. Analysis of dry weight ratio of stem-sheath, leaf, and panicle to total plant at middle and late stages of rice, the dry matter ratio of stem-sheath was the biggest at booting stage. But they continued to decrease with the growth, reached a minimum at maturity, and in each treatment decreased from 58.30%-64.20% to 27.95%-30.47%. Dry matter ratio of leaf was the biggest at booting stage, reduced from 35.80%-41.70% to 13.07%-14.62%. According to the survey, weeds in paddy field belong to seven families, eleven species. The weed densities of Echinochloa crusgalli, Monochoia vaginalis, Sagittaria pygmaea and Eleocharis yokoscensis were greater than others, accounting for 80.84% of field weeds. The treatment of MV-R-R had a significant effect on paddy weed density and the effect on inhibiting weeds was obvious better than other treatments. The treatment of RG-R-R was the lowest. By analyzing the relative abundance of weed species, the following conclusions could be drawn. The basic weed community compositions of the MV-R-R and RG-R-R were Monochoia vaginalis+ Echinochloa crusgalli+Eleocharis yokoscensis, but that of the RP-R-R and MS-R-R were Monochoia vaginalis+ Echinochloa crusgalli+ Sagittaria pygmaea. The species richness of the RG-R-R were maximum, significantly higher than other treatments. For the Shannon index, the species diversity of the treatment of winter planting-ryegrass was the highest, while the MV-R-R was the lowest. From the point of view of Simpson index, the weed dominance of MV-R-R was the highest, while the RG-R-R was the lowest. From the point of view Pielou evenness index, the weed evenness of the MV-R-R was higher than other treatments, but the difference was not significant. While the weed evenness of the other winter planting-green manure pattern decreased, of which the RG-R-R was the lowest.【Conclusion】In conclusion, the treatment of milk vetch-rice-rice can ensure higher dry matter accumulation and yield potential, which have a significant impact on weed species and density. Also it can help to improve weed uniformity and decrease the harm of dominant species of weeds in paddy field.
    HORTICULTURE
    Genome-wide Identification and Expression Analysis of Auxin Response Factor (ARF) Family in Cucumber
    SHENG Hui-1, 2 , QIN Zhi-Wei-1, LI Wen-Bin-3, ZHOU Xiu-Yan-1, WU Tao-1, XIN Ming-1
    Scientia Agricultura Sinica. 2014, 47(10):  1985-1994.  doi:10.3864/j.issn.0578-1752.2014.10.012
    Abstract ( 549 )   HTML ( 4 )   PDF (639KB) ( 568 )   Save
    References | Related Articles | Metrics
    【Objective】 The objective of this study is to identify the cucumber auxin response factor (ARF), forecast the small RNAs and verify the relationship between ARF with small RNAs and auxin. The expression pattern of ARF during seed germination was analyzed and the effect of ARF on the process of parthenocarpy and seed germination was deduced. 【Method】 The Arabidopsis and rice ARF proteins were used to search the cucumber genome database. Then, the retrieved cucumber ARF family structure was analyzed and the small RNAs were predicted. The predicted gma-MIR160o precursur was built into the pCAMBIA2301. By Agrobacterium-mediated method, it was imported into parthenocarpy cucumber varieties. Transgenic plants were validated by RT-PCR. Using real-time RT-PCR method, the expression patterns of ARF were analyzed in auxin treatment, flowing and seed germination. 【Result】 By comparison with the Arabidopsis and rice ARF protein sequences, there are 18 cucumber ARF protein sequences. ARF proteins were divided into four classes. The number of exons varied from 2 to 18, and the structure was similar among the same class. Phylogenetic tree showed that the similarity of 18 genes was not high. Small RNAs corresponds to ARF genes in cucumber were found. Csa010564, Csa011935, Csa015176, Csa020560 and Csa022361 were miR160 targets. Transgenic test further exhibited mRNA abundance of Csa010564, Csa011935 and Csa015176 decreased, while Csa020560 and Csa022361 rose slightly, indicating that Csa010564, Csa011935 and Csa015176 were miR160 targets. The results of real-time RT-PCR exhibited that mRNA abundance of Csa007296, Csa011935 and Csa015176 in roots, stems and leaves were higher than wild type, indicating the expressions of these genes were positively regulated by auxin. Meanwhile, the expressions in leaves and female flowers were decreased on the second flowering day, while the expression of the ovary was the opposite, especially Csa011935 and Csa015176, indicating that ARF genes play a crucial role in the development of the ovary. In the experiment of the auxin treatment, the expressions in different tissues were up-regulated. The expression of ARF genes in the seed germination was analyzed. The results showed that the expression peak of most genes were 12 h and 48 h in imbibition. 【Conclusion】 The ARF genes were regulated by auxin and the corresponding small RNAs. ARF genes may play a key role in the parthenocarpy and seed germination of cucumber .
    Effects of Aeration Cultivation on Root Architecture and Nitrogen Metabolism of Young Peach Trees
    XIAO Yuan-Song-1, PENG Fu-Tian-1, ZHANG Ya-Fei-1, QI Yu-Ji-1, WANG Gui-Fang-1, WANG Xin-Liang-2, SHU Huai-Rui-1
    Scientia Agricultura Sinica. 2014, 47(10):  1995-2002.  doi:10.3864/j.issn.0578-1752.2014.10.013
    Abstract ( 463 )   HTML ( 3 )   PDF (559KB) ( 619 )   Save
    References | Related Articles | Metrics
    【Objective】 This study was conducted to evaluate the effects of aeration cultivation on root architecture and nitrogen metabolism of young peach trees in order to lay a foundation for finding out the role of oxygen in the peach tree root growth and development.【Method】Two-year-old peach tree ‘Chunmei’ was selected to study the effects of aeration cultivation on soil O2 content, root activity, root architecture and nitrogen metabolism of young peach trees. Plastic box with uniform small holes at the bottom was used as the aerobic cultivation device. There were two treatments including the control (non-aeration) and aeration cultivation. The change of soil O2 concentration, root activity, root total nitrogen and root transaminase activity was determined in the peach tree growing season. The professional edition of root analysis system WinRHIZO was used to determine the parameter of root architecture after the new shoots slightly stop growing.【Result】Aeration cultivation improved soil O2 content. After aeration cultivation, the total root length, total root surface area, number of first lateral roots and second lateral roots, number of tips, total root volume, number of forks, number of cross increased by 50.53%, 42.66%, 13.64%, 18.51%, 44.94%, 5.48%, 37.01% and 54.41%, respectively compared with the control. The average length of first lateral roots and root average diameter decreased. The angle between first lateral roots and vertically downward direction was decreased, the number of small angle increased, and root tended to vertically distribution under aeration cultivation. The dry matter of roots which the diameter was less than 2 mm was significantly higher than control and the dry matter of roots which the diameter was greater than 5 mm was decreased under aeration cultivation. The activity of root system, the activities of NR, GOT, GPT and the content of root total nitrogen were higher than the control under aeration cultivation and they increased 19.04%, 29.80%, 6.56%, 19.91% and 18.90%, respectively. After aeration cultivation, the dry matter accumulation and stem of young peach trees were higher than the control. 【Conclusion】 Aeration cultivation can increase the soil O2 concentration and promote the occurrence and growth of fine roots. It can induce root straight down growth and improve the level of the root nitrogen metabolism. It is advantageous to accumulate the dry matter and promote the growth and development of young peach trees.
    STORAGE·FRESH-KEEPING·PROCESSING
    Study on Relationship Between Myofibril Characteristics and Meat Quality of Chicken Raw Meat
    WANG Chun-Qing-1, LI Xia-1, ZHANG Chun-Hui-1, CHEN Xu-Hua-1, SUN Hong-Mei-1, LI Yin-1, LI Hai-1, HE Lei-Tang-2
    Scientia Agricultura Sinica. 2014, 47(10):  2003-2012.  doi:10.3864/j.issn.0578-1752.2014.10.014
    Abstract ( 555 )   HTML ( 5 )   PDF (1016KB) ( 1033 )   Save
    References | Related Articles | Metrics
    【Objective】The relationship between myofibril characteristics and meat quality of breast of different chicken varieties was investigated. The purpose of the present study was to provide a scientific basis for selection of special varieties and understanding of the effect of raw meat quality on the quality of meat products. 【Method】The microstructures and ultrastructures of breast muscle myofibril of eight Chinese native chickens were observed by scanning electron micrograph (SEM) and transmission electron microscope (TEM) , the quantitative analysis of myofibril characteristics was conducted by Image-Pro Plus 6.0, at the same time cooking loss, shear force, texture profile analysis (TPA) and myofibril fragmentation index (MFI) were measured. The correlation between myofibril characteristics and processing features was established by correlation analysis. The Statistic Analysis System 9.2 (SAS9.2) was used to analyze the variance, multiple comparison and correlation.【Result】Eight Chinese native chickens showed a significant difference in basic chemical compositions, colour, pH, tenderness, water holding capacity, texture properties, fibre diameter, fibre density, sarcomere length and MFI (P<0.05). The water content of Silkie was significantly higher than the other varieties (P<0.05) , and the Chai hens’ was the lowest. The protein contents of eight Chinese native chickens were ranging from 22.03% to 24.53%, and the extent of variation was minor. The protein content of Princess chicken was the lowest, but its fat content was the highest. The lightness and redness of Bantam were significantly higher than the other varieties (P<0.05). The pH of Silkie was the highest. The shear forces of Princess chicken, Tsingyuan’s chicken, Silkie and Spring chicken were lower than the other varieties and the cooking loss of Silkie was the lowest. The fibre diameters of Princess chicken, Tsingyuan’s chicken, Silkie and Spring chicken were thinner, the fibre densities were denser; the sarcomere length of Tsingyuan’s chicken was the longest. MFI of Sanhuang chicken and Princess chicken were higher than the other varieties. The correlation analysis showed that the fibre diameter was positively correlated (P<0.05) with shear force, but the fibre density was negatively correlated (P<0.05) with shear force, the sarcomere length was negatively correlated (P<0.05) with cooking loss.【Conclusion】There was a significant correlation between myofibril characteristics and meat quality, the myofibril characteristics had an important effect on meat quality.
    Influence of Heating on Structure and Gel Properties of Myofibrillar Proteins from Chicken Breast Muscle
    YANG Yu-Ling, YOU Yuan, PENG Xiao-Bei, CHEN Yin-Ji
    Scientia Agricultura Sinica. 2014, 47(10):  2013-2020.  doi:10.3864/j.issn.0578-1752.2014.10.015
    Abstract ( 453 )   HTML ( 3 )   PDF (538KB) ( 1146 )   Save
    References | Related Articles | Metrics
    【Objective】This study was designed to investigate the influence of heating on myofibrillar proteins(MP) secondary structure and gel properties, and to reveal the relationship between MP secondary structure and gel properties.【Method】Forty-day-old commercial AA broilers were slaughtered. The breast muscle was stored at -18℃ before MP was extracted. The MP secondary structure was measured using a circular dichroism spectra to determine the content of α-helix, β-sheet, β-turn and random coil during heating. The values of G' and Tanδ were continuously measured using a rheometer during heating. The influence of heating temperature on textural properties of MP gel prepared under different temperatures was measured using a textural analyzer. Spin–spin relaxation time (T2) of the gels prepared under different temperatures was measured using a NMR Analyzer in order to investigate the water distribution of gels. SPSS17.0 software was used to analyze the data such as correlation analysis so as to illustrate the relationship between the heating temperature and protein structure and gel properties. 【Result】 Heating temperature influenced significantly MP secondary structure. The α-helix content declined from 95.77% to 45.05% as temperature increased from 30℃ to 80℃. The α-helix content declined slightly as temperature increased from 30℃ to 40℃ and from 70℃ to 80℃, declined abruptly between 40℃ and 70℃ (P<0.05). The β-sheet content increased from 0.20% to 12.65% as temperature increased from 30℃ to 80℃. The decline in α-helix content indicates the unfolding of a protein molecule. The increase in β-sheet content indicates the aggregation of unfolding protein molecules. Heating temperature influenced rheological properties, textural properties and water distribution of MP. G' values began to increase at about 42℃ indicating the starting of protein gelling. G’ values showed a sharp increase between 42℃ and 50℃ (177 Pa) with a subsequent decrease between 50℃ and 55℃ and a final increase between 55℃ and 75℃. Hardness values of MP gel increased as the temperature of the gel prepared rose from 40℃ to 75℃ and reached the maximum value of 51.4 g at 75℃. Springiness values reached the maximum value of 0.754 at 55℃. T2 curves of MP gel usually contained 3 peaks and T22 means immobile water. T22 values of the gels decreased from 403.7 ms to 265.6 ms as the gel preparing temperature rose from 40℃ to 60℃, which indicated that water mobility decreased as temperature rose from 40℃ to 60℃. Heating temperature and β-sheet content showed a significant positive relationship to G' and hardness of gel (P<0.01), and the correlation coefficients were all over 0.849. The correlation analysis indicated that heating caused MP molecules unfolding, aggregating, gelling, and led to significant change of G' and hardness of MP gel. α-Helix and β-sheet, which didn't show a significant relationship to springiness and T22 of the MP gel. It was found that heating led to MP molecules unfolding, aggregating, gelling simultaneously at temperature over 40℃ by analyzing the influence of heating temperature on α-helix, β-sheet content and G’. The unfolding MP molecules rearranging to β-sheet was the key factor for the increase of G’ values. The unfolding MP molecules rearranging to β-sheet was also the key factor for the increase of hardness values by analyzing the influence of heating temperature on β-sheet content and hardness values of MP gel.【Conclusion】The α-helix content declined and β-sheet content increased as temperature increased from 30℃ to 80℃. Heating led to significant changes of protein secondary structure. G' values began to increase and the values of Tanδ began to decrease at about 42℃, which indicated the starting of protein gelling. Gel hardness values reached the maximum 51.4 g at 75℃. Heating temperature and β-sheet content showed a significant positive relationship to G' and hardness of the gel. The increase of β-sheet content was the key factor for the increase of G’ and hardness values of the MP gel.
    ANIMAL SCIENCE·VETERINARY SCIENCERE·SOURCE INSECT
    Study of a True Hermaphrodite Pig
    ZHOU Yi-1, 2 , ZHAO Hai-Quan-2, LIU Yu-Qing-2, YU Hui-2, SHUAI Su-Rong-1, LI Hua-1, 2
    Scientia Agricultura Sinica. 2014, 47(10):  2021-2029.  doi:10.3864/j.issn.0578-1752.2014.10.016
    Abstract ( 359 )   HTML ( 1 )   PDF (870KB) ( 548 )   Save
    References | Related Articles | Metrics
    【Objective】 The morphological, anatomical, cytogenetical and histopathological study in a true hermaphrodite pig was conducted, which aimed at elucidating the basis of genetics and reproductive development, optimizing germplasm resources for pig production. 【Method】 A large white hermaphrodite pig at five months age was used as the experimental group, versus three littermate normal male and female pigs were used as control group. The morphology of external and internal reproductive organs was examined. SRY gene was tested by PCR. Karyotype analysis was performed on metaphases obtained from conventional peripheral blood lymphocyte cultures, and was G banded and C banded. Venous sex hormones including testosterone (T), estradiol (E2), luteinizing hormone (LH), follicle-stimulating hormone (FSH), progesterone (PRG) and prolactin (PRL) were tested using radioimmunoassay. Gonads (2 cm×2 cm) were fixed with 10% neutral formaldehyde, routinely prepared as conventional paraffine sections, and then stained with haematoxylin and eosin (HE stain). The histological sections were observed and documented in light microscope. Hypothalamus and pituitary (2 mm×2 mm) were fixed with 2.5% glutaraldehyde, and ultra structure analysis was observed under the electron microscopic sections. 【Result】 The external genitals had female phenotype with an enlarged clitoris, the anus was joined with the vulva and a testis with well-developed scrotum was on the left in the hermaphrodite pig. In the hermaphrodite pig and female pigs, the diploid chromosome number was 38, XX, karyotype was 10sm+4st+12m+12t, and SRY gene was negative. No differences were found in G-banding pattern and most C-bandings with round pattern were occurred on chromosomes 1, 3, 4, 6, 8, 9, 10, 13, 14 and 16. The chromosome relative length and the arm ratio showed no significant difference (P>0.05) between the experimental group and the female pigs. The values of T and E2 in hermaphrodite pig were at middle level compared with that in the normal male and the female pigs, but LH, FSH, PRG and PRL were relatively higher, and the ratio of LH/FSH was obviously lower than that in the female pigs. After dissection the hermaphrodite pig, the gonads were shown both ovotestes, the left one with an epididymis, showing the regressive uterine body, uterine horns and vagina. A phallus was hidden in clitoris. Ovotestis was mixed with testis and ovary, showing regressive columnar epithelial cells, normal leydig cells, no spermatogonium and its debris. Epididymis was observed with normal pseudostratified ciliated columnar epithelium cells and no spermatozoal content or cell debris in the lumen. Endometrium was shown degeneration of endometrial lining combination with some of the normal endometrial glands. Secretory cells of hypothalamus and pituitary gland were more developed in the experiment group than that in the control group. Gonadotropin-releasing hormone (GnRH) neures were shown large nucleus, increased and fused organelle. Pituitary was observed mainly gonadotroph, of which quantity was increased and secretory granules were with different sizes in the hermaphrodite pig than that in the normal pigs. The quantity of lactotrophs and the electron density of secretory granules was larger in hermaphrodite pig than that in the female pigs. 【Conclusion】 These results indicated that the intersex pig belongs to a true hermaphrodite pig with no chromosome translocation, sex hormone disturbance and no breeding value.
    Dynamic Variation of Symbionts in Bumblebees During Hosts Growth and Development
    XU Long-Long, WU Jie, GUO Jun, LI Ji-Lian
    Scientia Agricultura Sinica. 2014, 47(10):  2030-2037.  doi:10.3864/j.issn.0578-1752.2014.10.017
    Abstract ( 478 )   HTML ( 3 )   PDF (575KB) ( 571 )   Save
    References | Related Articles | Metrics
    【Objective】 The objectives of this study are to examine microbial communities from the digestive tract of Bombus lantschouensis reared in the laboratory, and to analyze the specific bacteria spatio-temporally in different developmental stages of B. lantschouensis, which is the important foundation and basis for further studying the function of symbiotic bacteria in bumblebee. 【Method】The fragment of the bacterial 16S rDNA gene was PCR-amplified with the universal eubacterial primers 774F and 1391R and a 16S rDNA clone library of gut bacteria was constructed. Each single clone was picked and sequenced. The sequences were checked for chimeras, sequences of chimeric origin were removed from further analysis. Sequences obtained were analyzed by BLASTn and matched with valid reference sequences in the NCBI (National Center for Biotechnology Information) to determine the bacterial species types. The 16S rDNA gene primers of the specific bacteria Gilliamella apicola and Snodgrassella alvi were designed based on sequencing of bacterial taxonomic groups obtained from the clone library, then constructed recombinant plasmid using the specific bacteria primers and diluted the plasmid to 10 folds series for 5 concentration gradients after concentration determination. Total genomic DNA was extracted from egg, larva, pupa, and 0, 5th, 10th, 15th, 20th days worker bees. The bumblebee β-actin gene was selected as the reference gene, the quantitative real-time PCR (qPCR) was used to explore the quantity variation of symbionts during the different developmental stages of B. lantschouensis.【Result】A total of 213 clones were picked and sequenced, after Chimeras checking, 202 sequences were obtained and then divided into 16 OTUs. The sequence similarity with GenBank sequences was between 93%-99%. The phylogenetic analysis found that the sequences fell into 6 major lineages within the domain bacteria. Among them, 45% and 30% were respectively G. apicola and S. alvi, 10% was Bifidobacterium, 5% was Fructobacillus fructose, 2% was Lactobacillus, 2% was Flavobacterium aciduliphilum, and 6% was mixture of uncommon bacteria types. The qPCR result showed that G. apicola and S. alvi were detected in all development stages, the two bacterial species were similar in the quantity variation patterns with decreasing after increasing, finally reached the steady state. The quantity of G. apicola and S. alvi in egg, larva and pupa was very low, in 5th day significantly higher than those in other development stages, and then gradually reduced, stabilized after 15th day, the bacteria quantity in 20th day showed no difference with 15th day.【Conclusion】Four common symbiotic bacteria including G. apicola, S. alvi, F. fructose and Bifidobacterium were identified in the digestive tract of B. lantschouensis reared in laboratory. G. apicola and S. alvi are dominant bacterium among them. G. apicola and S. alvi both have horizontal and vertical transmission. The quantity of G. apicola and S. alvi in egg, larva and pupa was very low, and increased rapidly after worker bees emergence, stabilized after 15 days. The temporal variation of two dominant bacteria in B. lantschouensis may be related to the function of symbiotic bacteria in bumblebee.
    RESEARCH NOTES
    Comprehensive Evaluation of Salt Tolerance and Screening for Salt Tolerant Accessions of Naked Oat (Avena nuda L.) at Germination Stage
    CHEN Xin-1, ZHANG Zong-Wen-1, 2 , WU Bin-2
    Scientia Agricultura Sinica. 2014, 47(10):  2038-2046.  doi:10.3864/j.issn.0578-1752.2014.10.018
    Abstract ( 507 )   HTML ( 7 )   PDF (698KB) ( 780 )   Save
    References | Related Articles | Metrics
    【Objective】Salt tolerance of 278 naked oat accessions from different ecological zones at germination stage were comprehensively evaluated in order to provide a guide for identification and evaluation of salt tolerance of naked oat, and supply abundant materials of salt tolerance for breeding of salt tolerance as breeding parents.【Method】Identification for salt tolerant germplasm of naked oat was conducted in an artificial climate incubator with germination method on paper in petri dish under 1.2% NaCl aqueous solution and distilled water, respectively. The culture condition was constant temperature 25℃, relative humidity (70±5)%, 12 h light (6:00-18:00), light intensity 150 μmol?m-2?s-1 in the incubator. When the length of radicle was equal to that of kernel at least, and the shoot height was not less than 1/2 of seed length, the seed was considered as germinated. Germination potential of tested accessions was counted after 96 hours cultivation. Final germination rate, length of the longest primary root and seedling height were measured after 168 hours cultivation. These four traits were used to identify salt tolerance of tested accessions. Based on salt tolerance coefficients derived from four identification indices, the weight of each index was allocated according to variation coefficient of membership function value of four salt tolerance coefficients, and 278 naked oat accessions were evaluated for salt tolerance with the weighted membership function method and classified through cluster analysis.【Result】Compared with distilled water control, germination potential and germination rate of all accessions were declined except SHX88 and NM47, and the root length and seedling height of all accessions were suppressed by salt stress. There were differences among tested accessions based on the four kinds of identification indices. With the weighted membership function method and cluster analysis, salt tolerance of 278 naked oat accessions were comprehensively evaluated and categorized into five grades. Seventeen accessions were highly salt tolerant, 114 accessions were salt tolerant, 106 accessions were middle tolerant, 25 accessions were susceptible and 16 accessions were highly susceptible. Germination potential and germination rate were closer with salt tolerance at germination stage among the four identification indices, but germination rate was more variable than germination potential among tested accessions.【Conclusion】Germination rate is an efficient identification index for rapid identifying and preliminary screening of salt tolerant accessions. The weighted membership function method has good application value in the comprehensive evaluation of tolerance of naked oat to salt stress. SHX75 and other sixteen naked oat accessions which are highly tolerant to salt stress have provided a basis for breeding, cultivation and mechanism research of salt tolerance.
    Effects of Water and Nitrogen Management Patterns on Population Quality and Yield of Hybrid Rice Gangyou 527
    SUN Yong-Jian-1, MA Jun-1, SUN Yuan-Yuan-2, XU Hui-1, YAN Feng-Jun-1, DAI Zou-1, JIANG Ming-Jin-1, LI Yue-1
    Scientia Agricultura Sinica. 2014, 47(10):  2047-2061.  doi:10.3864/j.issn.0578-1752.2014.10.019
    Abstract ( 427 )   HTML ( 3 )   PDF (788KB) ( 517 )   Save
    References | Related Articles | Metrics
    【Objective】In order to provide a scientific basis for high water-fertilizer use efficiency of rice, the objective of this experiment was to study the effects of water and nitrogen (N) management patterns on population quality and yield of hybrid rice.【Method】Gangyou 527, an elite indica threeline hybrid rice cultivar widely planted in rice production in China, was used, which has high grain yield, extensive adaptability, and pest-resistance with growth duration of 145-150 days from sowing to maturity. The experiment was conducted to optimize N application, understand how different combinations of water and N management affect population quality of hybrid rice and yield, and study the correlations of population quality index and grain yield. Three irrigation regimes including submerged irrigation (W1), controlled alternate irrigation (W2), and dry cultivation (W3) combined with four N application managements at 180 kg?hm-2 of total N conditions were designed in the study. The four N application ratios were applied on different splits: (a) 2 splits: 70% basal and 30% 7 d after transplanting (DAT) (N1), (b) 3 splits: 50% basal, 30% 7 DAT, and 20% panicle N-fertilizer according to different leaf ages when 4th leaves emerged from the top (N2), (c) 4 splits: 30% basal, 30% 7 DAT, 40% panicle N-fertilizer equally when 4th and 2nd leaves emerged from the top (N3), (d) 4 splits: 20% basal, 20% 7 DAT, 60% panicle N-fertilizer equally when 4th and 2nd leaves emerged from the top (N4), in addition, no N application (N0) was designed as control. 【Result】 The results showed that there was an obvious interaction between irrigation regime and N application on dry matter accumulation and leaf area index (LAI) at the mainly growth stages, grain-leaf ratio at heading stage, net photosynthetic rate and yield. Decomposition analysis of water and nitrogen interaction effects showed that appropriate increase of N application ratio of later stage or W2 treatment had a positive effect on yield, the N application treatments had significant differences, and ranked as N3>N2>N1, and N4 treatment or W3 treatment resulted in a negative effect of water-nitrogen interaction. Compared to irrigation regimes, the results of water and nitrogen interaction showed that W2 treatment promoted the efficiency of N fertilizer, and achieved the purpose of promoted fertilizer by water. W2 treatment with suitable treatment of N3 application (30% basal, 30% tillering, 40% panicle N-fertilizer equally at 4th and 2nd leaves emerged from the top) was the best model in this paper and referred as the water-nitrogen coupling model, which could control the number of rice tillering, improve the rate of tiller panicle, guarantee the appropriate LAI and grain-leaf ratio at filling stage, increase the efficient leaf area ratio and population light transmission rate, and thus improving photosynthetic capacity at filling stage and the accumulation of photosynthetic products, and on the premise of effective panicle and seed-setting rate, the yield increased significantly. However, the other combinations of irrigation regimes and N application managements resulted in weakened advantages, or even resulted in the negative effects of water-nitrogen interaction and decreased of grain yield. Especially, either W3 treatment or high N application ratio of later stage (N4 treatment) resulted in yield reduction, and aggravated negative effect of water-nitrogen interaction. According to yield performance under W3, the proper decrement of panicle N-fertilize ratios could ease the negative effect of water-nitrogen interaction to some extents, and suitable panicle N-fertilizer should account for 20%-40%. Under W1, however, on the basis of 40%-60% base tillering N fertilizer, panicle N-fertilizer should account for 40%-60%. Correlation analysis indicated that there existed significantly or highly significantly positive correlations (r=0.589*-0.978**) between index of population quality and yield under water-nitrogen interaction, especially had positive correlations between yield and increasing amount of dry matter at filling stage and decrement of population light transmission rate from full-heading stage to 20 days full-heading stage.【Conclusion】The results suggest that rice plant growth could be improved and high grain yield could be achieved through integrating and optimizing water-fertilizer regulating techniques in rice production. W2 and suitable N3 combined application was considered to be optimum under the experimental conditions, optimum N management pattern was also N3 for W1. However, under W3 treatment, the ratio of panicle N-fertilizer application should be decreased, and N management patterns (50% basal, 30% tillering, and 20% panicle N-fertilizer at 4th leaves emerged from the top) were considered to be optimum for W3.
    Morphologic and Physiologic Characterization of an Ovule Abortion Mutant in Brassica napus
    XU Wang-Jie, FU Ying, DONG Hong-Li, CHEN Zhi-Fu, ZHANG Qin-Yun, MAO Shao-Shuai, HE Ya-Jun, QIAN Wei
    Scientia Agricultura Sinica. 2014, 47(10):  2062-2068.  doi:10.3864/j.issn.0578-1752.2014.10.020
    Abstract ( 397 )   HTML ( 2 )   PDF (648KB) ( 460 )   Save
    References | Related Articles | Metrics
    【Objective】The development of ovule is closely related with seed-setting and seed weight, which are components of seed yield in rapeseed. The investigation of morphologic and physiologic characterization of abortion mutant will benefit understanding the mechanism of development of ovule. 【Method】 In this study, OVA047,an ovule abortion mutant, was characterized in histological anatomy and investigated for the effects of nutrition of boron and temperature in Chongqing. Acetic red dyeing method was used to identify pollen fertility of OVA047. The buds of OVA047 which were about to open were selected for artificial emasculation and pollination. The ovary samples were taken and the pollen tube elongation was observed every 4 hours after artificial pollination. Foliar boron treatments were applied for one month seedlings of the normal materials and OVA047. Vegetative growth, pollen fertility and seed setting rate were investigated. Buds were artificially stripped, emasculated and pollinated, pollination time was tagged, statistical analysis was made for abortive rate in different periods after pollination. Daily average temperature and daily maximum temperature were recorded and the correlation between temperature and abortive rate was investigated. The data obtained were analyzed by using software SAS.【Result】 Normal sexual organisms and pollination could be detected and the pollen dye ability rate was 95.90%。Pollen tube could germinate and reach the ovary. The development of ovule was found in good by anatomy on 7 day and 14th day after pollination, but most of ovules stopped growth 20 days after pollination in OVA047, especially at the top of inflorescence with 0.8 seeds per pod 35 days after pollination, 4% of the control. The content of boron in leaf was increased with the content of foliar-applied boron treatment in both normal material and OVA047. No significant differences were detected between OVA047 and control in the content of boron in leaf in the same treatment of boron fertilization. However, in different treatments of boron fertilization, all the OVA047 still exhibited low seed-setting (3.2) and around 60% of ovule abortion ratio in the inflorescence while the control still exhibited normal seed-setting (29). Two years observation results showed that large-scale ovule abortion phenomenon at the top, middle and basal of the inflorescence occurred in the significant temperature rise period when OVA047 grown in Chongqing, the later ovule abortion was increased with the daily temperature. A strong and positive association was found between ovule abortive rate of OVA047 and daily maximum temperature.【Conclusion】The ovule abortion of OVA047 is not due to fertilization failure and possible does not relate with boron fertilization, but associate with temperature.