Loading...

Table of Content

    16 January 2016, Volume 49 Issue 2
    CROP GENETICS & BREEDING·GERMPLASM RESOURCES·MOLECULAR GENETICS
    Breeding Technique Innovation and Application of China’s Super Rice
    CHENG Shi-hua
    Scientia Agricultura Sinica. 2016, 49(2):  205-206.  doi:10.3864/j.issn.0578-1752.2016.02.001
    Abstract ( 629 )   HTML ( 21 )   PDF (211KB) ( 1394 )   Save
    References | Related Articles | Metrics
    Breeding Technology innovation of Indica-Japonica Super Hybrid Rice and Varietal Breeding
    LIN Jian-rong, SONG Xin-wei, WU Ming-guo, CHENG Shi-hua
    Scientia Agricultura Sinica. 2016, 49(2):  207-218.  doi:10.3864/j.issn.0578-1752.2016.02.002
    Abstract ( 724 )   HTML ( 14 )   PDF (1240KB) ( 981 )   Save
    References | Related Articles | Metrics
    【Objective】The indica-japonica super hybrid rice breeding technology innovation and practice had been carried out in to improve with problematic characters, such as longer growth period, lower seed setting rate and lower seed yield existing in the utilization of heterosis between indica rice and japonica rice. 【Method】Japonica maintainer lines with early flowering and high rates of stigma exsertion were developed by indica-japonica intergression crossing. Using these materials, high outcrossing rate japonica CMS lines were bred. Indica-japonica intermediate type restorer lines with wide compatibility were bred by means of indica-japonica intergression crossing, molecular marker assisted selection of wide compatibility gene and directional selection of indica and japonica components. The main agronomic traits of these type’s Cheng’s index, wide compatibility and gene restoring spectrum were compared with the japonica restorer line. The light-temperature reaction type and the outcrossing rate were also compared between japonica-indica hybrid rice and indica-japonica hybrid rice. The japonica-indica hybrid rice and indica-japonica hybrid rice were bred from japonica CMS line Chunjiang 16A, indica CMS line Wufeng A and the indica-japonica intermediate type restorer lines CH58, C84 and C927 with wide compatibility. 【Result】The japonica CMS lines Chunjiang 16A, Chunjiang 99A and Chunjiang 23A with early flowering and/or high rate of stigma exsertion were developed by indica-japonica intergression crossing, and their seed yield increased significantly. The indica-japonica intermediate type restorer lines CH58, C84 and C927 with wide compatibility were bred, which had characteristics of large panicles, strong stems, good wide compatibility and wide restoring spectrum. The F1 of late season japonica CMS lines/indica-japonica intermediate type restorer lines with wide compatibility showed stronger photoperiod-sensitivity, while the F1 of middle season japonica CMS lines/indica-japonica intermediate type restorer lines with wide compatibility had increased temperature-sensitivity, but the light-temperature reaction type F1 were different between early season indica CMS lines/indica-japonica intermediate type restorer lines with wide compatibility. Larger stigma exsertion rates of CMS lines and smaller differences in spikelet flowering rates before noon of parents were beneficial in increasing the outcrossing rate of the japonica-indica hybrid rice and indica-japonica hybrid rice. Chunyou 84 and Wuyou 84 which developed from japonica CMS line Chunjiang 16A, indica CMS line Wufeng A and the indica-japonica intermediate type restorer line C84, and showed the advantage of large panicle, strong heterosis, high yield potential, high lodging resistance, high seed setting rate and strong cold tolerance. These two were released provincially.【Conclusion】 Japonica CMS lines with early flowering and high rates of stigma exsertion were developed by indica-japonica intergression crossing. The indica-japonica intermediate type restorer lines with S5-n gene and wide restoring spectrum were different from the ordinary japonica restorer line. The F1 of middle season japonica CMS lines/indica-japonica intermediate type restorer lines with wide compatibility were temperature-sensitive, with a marked benefit to shorten the whole growth period. Larger stigma exsertion rates of CMS lines and smaller differences on spikelet flowering rates before noon of the parental lines were effective in increasing the outcrossing rates of the japonica-indica hybrid rice and indica-japonica hybrid rice. The indica-japonica super hybrid rice Chunyou 84 was released provincially.
    Comparison the Heterosis of Indica-Japonica Hybrids and Japonica-Japonica Hybrids Using InDel Markers
    GUI Jun-mei, WANG Lin-you, FAN Xiao-juan, QI Yong-bin, ZHANG Li-xia, FAN Hong-huan, JIN Qing-sheng, WANG Jian-jun
    Scientia Agricultura Sinica. 2016, 49(2):  219-231.  doi:10.3864/j.issn.0578-1752.2016.02.003
    Abstract ( 493 )   HTML ( 8 )   PDF (798KB) ( 685 )   Save
    References | Related Articles | Metrics
    【Objective】With the development and improvement of breeding technology in indica-japonica hybrid rice, it has been possible to explore inter-subspecific heterosis directly to develop high-yielding rice varieties. It is highly significant to be able to detect gene frequencies of indica or japonica accurately, identify indica-japonica attributes and cultivar classification, and to predict competitive heterosis by genetic distance for indica-japonica hybrid rice breeding and cultivar classification using InDel molecular mark and sophisticated technology. 【Method】Twenty-four indica-japonica hybrids or japonica-japonica hybrids, recently bred by different breeding units in Zhejiang province, were collected to analyze using eighteen pairs of primers selected from the InDel molecular marker. The gene frequencies of japonica genomics were detected by the Wang’s reported method, and tested materials were judged for different attributes. Genetic distance (GD) among tested materials was assessed by InDel molecular markers using Nei’s calculation method.. The genetic similarity (GS) was assessed using UPGMA cluster analysis of genetic similarity. Principal component analyses (PCA) were conducted using SPSS 17.0 statistical analysis software to assign InDel bands, then, on the basis of the average values of the eigenvectors of the first and second principal components, a scatterplot was created. Ten agronomic important characteristics, i.e. period duration, plant height, spikelet number per panicle, seed setting, 1000-grain weight and grain weight per plots were investigated for analysis of competitive heterosis. The relationships of competitive heterosis of japonica- japonica hybridsor indica-japonica hybrids with GD values to control cultivar were determined. 【Result】Eighteen pair of InDel primers could amplify all materials to obtain special indica bands, japonica bands and indica-japonica hybrid bands. According to calculated frequencies of japonica genes, these materials were accurately judged different to have indica-japonica attributes, and were divided into six clusters, twelve hybrids belonging to indica-japonica hybrids, and another thirteen hybrids placed into japonica-japonica hybrids. Again, using cluster analysis of InDel markers, this distribution was verified. With the results of PCA analysis, we show that all varieties classify into three non-overlapping tzones, an indica zone, typical japonica -japonica zone, and a japonica cline-intermediate type zone. Comparison of the average of plot yields in two-year trials, we found that the yieldsof indica-japonica hybrids increased by 12.5% and 14.9% over that of japonica-japonica hybrids, expressing outstanding yield advantages. Upon analysis of ten agronomic characters between the two type hybrids, total spikelet numbers and fertile spikelet numbers of indica-japonica hybrids were significantly increased by about 30%. We suggest that the attribute of larger panicles is the major contribution factors to yield increases. After comparative analyses of the genetic distances (GD) relationship of tested varieties to the control Jiayou 2, we found no significant relations the group of japonica-japonica hybrids, whereas have most significant positive relations with traits of panicle length and 1000-grain weight, but has a significant negative relations with the grain density. 【Conclusion】Using InDel molecular mark technology is powerful and effective in its ability to detect gene frequencies of japonica in various types of cultivars, and to identify their indica-japonica attributes or classify their cultivar types. The indica-japonica hybrid rice expressed significant competitive heterosis in grain yield, the major contribution of heterosis was more spikelets per panicle.
    QTL Mapping for Standard Heterosis of Yield Traits in Rice
    ZHU Yu-jun, CHEN Jun-yu, ZHANG Zhen-hua, ZHANG Hong-wei, FAN Ye-yang, ZHUANG Jie-yun
    Scientia Agricultura Sinica. 2016, 49(2):  232-238.  doi:10.3864/j.issn.0578-1752.2016.02.004
    Abstract ( 456 )   HTML ( 11 )   PDF (400KB) ( 606 )   Save
    References | Related Articles | Metrics
    【Objective】 This study was conducted to determine quantitative trait loci (QTLs) associated with the standard heterosis of yield traits and to analyze the genetic basis of standard heterosis in rice. 【Method】 A recombinant inbred line (RIL) population was derived from crosses between rice restorer lines Teqing and six IRBB lines that are near isogenic lines in the genetic background of IR24. A testcross population was also constructed by crossing the 204 RILs to male sterile line Zhong 9A. The 204 sets of RILs and corresponding F1 were grown side by side for two years in the same trial site. They were planted in two replications. At maturity, the middle four plants of each replication for each line were harvested together. The number of panicles per plant (NP), number of grains per panicle (NGP), number of spikelets per panicle (NSP), spikelet fertility (SF), 1000-grain weight (TGW) and grain yield per plant (GY) were measured. Mean values over the two replications were used for data analysis. A data set derived by subtracting the trait value of a RIL from that of its corresponding F1 was used for QTL analysis using QTLNetwork 2.0. A putative QTL was claimed using a genome-wise type I error of P<0.05 determined by 1000 permutations. 【Result】 Significant positive correlations between the RILs and F1s were observed for all the six traits. The correlation coefficients were highest for TGW (0.903), lowest for NP (0.333) and GY (0.357), and intermediate for SF (0.406), NGP (0.448) and NSP (0.680). A total of 16 QTLs distributed on chromosomes 2, 3, 5, 6, 8 and 10 were detected, including three (3) for NGP, four (4) for NSP, three (3) for SF, four (4) for TGW, and two (2) for GY. The phenotypic variance explained by a single QTL ranged from 1.7 % to 22.1 %. All three QTLs affecting NGP showed higher standard heterosis for Zhong 9A/IR24 than Zhong 9A/Teqing. For NSP, SF and TGW, three, two and two QTLs had higher standard heterosis for Zhong 9A/IR24 than Zhong 9A/Teqing, and one, one and two QTLs were higher in standard heterosis for Zhong 9A/Teqing than Zhong 9A/IR24. Of the two QTLs associated with GY, qGY2 overlapped with qNGP2 for NGP and qNSP2 for NSP, and qGY10 overlapped with qNGP10 for NGP and qSF10 for SF. All six QTLs showed higher standard heterosis for Zhong 9A/IR24 than Zhong 9A/Teqing. 【Conclusion】 F1 performance was correlated with both parental performance and F1 heterosis. QTLs for standard heterosis play an important role in the genetic control of F1 performance of yield traits in rice.
    Research Progress and Related Problems on japonica Super Rice in Northern China
    XU Zheng-jin, CHEN Wen-fu
    Scientia Agricultura Sinica. 2016, 49(2):  239-250.  doi:10.3864/j.issn.0578-1752.2016.02.005
    Abstract ( 490 )   HTML ( 21 )   PDF (447KB) ( 804 )   Save
    References | Related Articles | Metrics
    China’s super rice research project was initiated by the Ministry of Agriculture in 1996. In the past 20 years, China has been a leader in super rice research, including genetic and physiological basis of super-high yielding or theory and practice for super rice breeding, and indica super hybrid rice in south or conventional japonica super rice in north. These research provided scientific and technical basis for improving production potential and converting sciences and technology to realistic productivity, and made outstanding contribution for maintaining China the international advanced level on rice science. Research progress of japonica super rice in Northern China, including the development of super rice, establishment of technical route, new variety breeding and demonstration promotion, basic research in physiological and genetic were reviewed in this paper. Meanwhile, some related physiological and genetic issues of Northern japonica super rice were discussed: The Northern japonica rice in recent years kept high levels on yield and quality, and the chalk white character and other appearance qualities have been improved, without significant contradiction between yield and main quality traits when yield no more than 9 t·hm-2, and the yield and quality can reach a new balance at a higher level. Analysis of Northern japonica rice regional test results showed that extending growth period to increase yield was unsatisfactory, also not work by increasing plant height, while improving the resistance to rice blast was one of the important breeding targets for Northern japonica rice. The seed density of Northern japonica rice is generally high, but the negative impact on the yield components and the main quality traits is relatively small, which can be thought that Northern japonica rice seed density is in an appropriate range through the untiring efforts of the breeders. Grain length-width ratio is a main factor determining indica and japonica rice milling quality, and less impact on the appearance quality difference between subspecies. Chinese indica rice milling quality has been improved significantly in recent years, difference between indica and japonica rice decreases. The appearance quality of indica and japonica rice has improved significantly, but the difference still exists between indica and japonica. On the basis of full summarizing Chinese super rice research achievements and experience in the past 20 years, the super rice research directions and goals in the future should be determined. Long-term stability research support mechanism according to the ecological regions should be established instead of stage yielding goals; small area yield evaluation should be changed to the assessment of large area stable yield increase. The basic theory and key technology research should be targeted according to the ecology, production and varieties of Northern japonica rice, such as the genetic and physiological and ecological mechanism of indica and japonica yield and quality. From the molecules, cells, tissues, organs, individual and population levels, comprehensive evaluation of erect panicle gene EP1 function should be further studied to effectively improve quality of both indica and japonica hybrid varieties with big and erect panicles. We should make full use of the research achievements of molecular biology and technology, and make a breakthrough on rice blast resistance, cold resistance and salt-tolerant germplasm innovation and breeding.
    TILLAGE & CULTIVATION·PHYSIOLOGY & BIOCHEMISTRY
    Effects of Exogenous Nitric Oxide on Photosynthesis of Maize Seedlings Under Drought Stress
    SHAO Rui-xin, LI Lei-lei, ZHENG Hui-fang, XIN Long-fei, SU Xiao-yu, RAN Wu-ling, YANG Qing-hua
    Scientia Agricultura Sinica. 2016, 49(2):  251-259.  doi:10.3864/j.issn.0578-1752.2016.02.006
    Abstract ( 513 )   HTML ( 5 )   PDF (1565KB) ( 1021 )   Save
    References | Related Articles | Metrics
    【Objective】To evaluate the effects of exogenous nitric oxide on the photosynthesis of maize (Zea mays L.) under drought stress. 【Method】The hydroponic experiment was conducted in a growth chamber with the Zhuyu 309 as the material. After being pretreated with sodium nitroprusside (SNP) for three days, these materials were simulated drought stress with 20% PEG-6000 for another three days. The changes of maize seedling’s growth, gas exchange, and chlorophyll fluorescence parameters, chloroplast ultrastructure and expression of D1 protein were investigated; 【Result】The photosynthetic rate (Pn), stomatal conductance (Gs), PSII maximum photochemical efficiency (Fv/Fm), PSII potential activity (Fv/Fo) were decreased by 68.4%, 87.2%, 15.8%, 31.3%,respectively under drought stress; The parameters of relative variable fluorescence intensity at J-step (Vj) and dissipated energy flux per reaction center (DIo/RC) increased by 20.9% and 21.2%. The ultrastructure of chloroplast in the leaf was destroyed and the structure of stacked grana was disintegrated. Moreover, the osmiophilic grains increased and the chloroplast was slowly divorced from the cell wall due to the drought. The content of D1 protein decreased significantly with Western-blotting analysis. However, with the treatment of SNP and then drought stress, the Pn, Gs, Fv/Fm, Fv/Fo were increased by 56.6 %, 202.5 %, 15.8 %, 30.7 % and the Vj decreased by 22.7% and 25.4% compared with the drought stress. The thylakoid lamellae arranged regularly and the grana were clear; and the relative amounts of D1 protein increased by 94.7%. The above changes were related to the increased NO content after SNP pretreatment under drought condition.【Conclusion】These results suggested that NO is involved in regulating the D1 protein expression and stabilizing the structure and function of PSII reaction centers to improve photosynthesis and growth of maize seedlings, which improved the adaptability of maize seedlings to drought stress. 
    Maturity Group Classification and Planting Regionalization of Soybean Varieties in the Inner Mongolia
    HU Xing-guo, SONG Wen-wen, WEI Yun-shan, SUN Bin-cheng, LI Qiang, CHAI Shen, SUN Ru-jian, SHAO Yu-bin, REN Ke, DING Su-rong, WU Cun-xiang, WU Ting-ting, ZHANG Wan-hai, HAN Tian-fu
    Scientia Agricultura Sinica. 2016, 49(2):  260-271.  doi:10.3864/j.issn.0578-1752.2016.02.007
    Abstract ( 500 )   HTML ( 4 )   PDF (1354KB) ( 781 )   Save
    References | Related Articles | Metrics
    【Objective】The Inner Mongolia Autonomous Region is one of the areas with the most abundant soybean ecological types in China. Understanding the diversity and distribution of the soybean varieties according to their maturity groups (MGs) in the region is not only of great importance for rational distribution and exchange of the germplasm, but also providing a model for soybean varietal maturity group classification and planting regionalization of the country. 【Method】To classify soybean varieties from the region into different maturity groups, 21 standard varieties which represent MG000, MG00, MG0, MGⅠ, MGⅡ and MGⅢ of soybean were introduced from North America as references in this study. In the field tests, 120 local varieties collected from the major soybean producing areas were planted in Zhalantun, Chifeng, Hohhot, Hangjin Rear Banner and Ejin Banner together with the MG reference varieties. Fifteen plants with the similar growing tendency were observed, and the dates of VE (emergence), R1 (beginning bloom), R7 (beginning maturity) and R8 (full maturity) were recorded. The method of "Classifying MG by Individual Years" was used for maturity group classification of the varieties. Geographical distribution and the north boundary of the representative varieties in the Inner Mongolia Autonomous Region were surveyed. 【Result】Varieties from the Inner Mongolia Autonomous Region were classified into 7 MGs of MG0000, MG000, MG00, MG0, MGⅠ, MGⅡ and MGⅢ. Three varieties matured earlier than MG000 were classified into MG0000, and 6, 20, 43, 35, 8, and 5 varieties were respectively classified into MG000, MG00, MG0, MGⅠ, MGⅡ and MGⅢ. The MG0000 varieties were mainly distributed in the northeast foothill area of Daxinganling Mountains and northeast section of Hulunbuir Plateau. The MG000 varieties were distributed in the east foothill area of Daxinganling Mountains. The MG000 varieties were distributed in west section of Hulunbuir plateau and the south and north alpine areas of Yinshan Mountains. The MG00 varieties were distributed in cool area of Yinshan Mountains and east and south section of Daxinganling Mountains. The MG0 varieties were distributed in Hulunbuir and Xingan League traditional agricultural regions in the Nen River valley at the eastern Daxinganling Mountains, Tongliao city, the mountainous area of north Chifeng and the warm areas of the Yinshan Mountains outer hill. The MGⅠvarieties were distributed in the cool-warm area of southeast section of Daxinganling Mountains, Chifeng hilly mountains and south foothill area of the Yinshan Mountains. The MG Ⅱ varieties were distributed in mild area of the south section of Daxinganling Mountains, Tumochuan Plain at south foothill area of Yinshan Mountains and Liangwai region of the Hetao Plain. The MG Ⅲ varieties were distributed in West Liaohe Plain warm area, Daqing Mountain gully slope area,Hetao Plain irrigated area and Alxa Plateau oasis area. According to the MGs and planting area of the test varieties and referring to the agricultural regionalization and meteorological data, soybean planting regionalization of the Inner Mongolia Autonomous Region was proposed, and soybean MG geographical distribution map in the Inner Mongolia Autonomous Region was drafted. In addition, the variety introducing scheme in the Inner Mongolia Autonomous Region and eco-regional adjustment plan for the uniform tests were proposed. 【Conclusion】Soybean varieties in Inner Mongolia were distributed widely in geological regions and diverse in MGs and ecological types. The MG classification could optimize the distribution, strengthen the exchange of soybean germplasm within and out of the region, highlight the targets of soybean breeding and extension, and accelerate the broad utilization of the varieties.
    PLANT PROTECTION
    Genetic Diversity of Fusarium pseudograminearum Collected from Henan and Hebei Winter Wheat Regions
    HE Xiao-lun, ZHOU Hai-feng, YUAN Hong-xia, SHI Yan, SUN Bing-jian, LI Hong-lian
    Scientia Agricultura Sinica. 2016, 49(2):  272-281.  doi:10.3864/j.issn.0578-1752.2016.02.008
    Abstract ( 434 )   HTML ( 3 )   PDF (1335KB) ( 506 )   Save
    References | Related Articles | Metrics
    【Objective】 Fusarium pseudograminearum is the dominant pathogen causing wheat crown rot. The objective of this study is to reveal the genetic diversity of F. pseudograminearum populations collected from Henan and Hebei winter wheat regions using inter-simple sequence repeat (ISSR) technology. 【Method】 F. pseudograminearum populations containing 166 isolates collected from Henan and Hebei winter wheat regions were amplified using 17 ISSR primers. Genetic diversity parameters were calculated by POPGENE version l.32 software. According to the genetic similarity coefficient of different geographical populations, the group clustering analysis was conducted using NTSYSpc version 2.11 software. 【Result】Seventeen ISSR primers which could amplify more polymorphic loci were screened from 97 ISSR primers. The genetic diversity of 166 F. pseudograminearum isolates collected from Henan and Hebei winter wheat regions was analyzed with 17 primers. The amplification results showed that 234 fragments were amplified, and 218 fragments displayed polymorphic which accounted for 93.16% in the total amplified fragments. The average number of bands amplified per primer was 13.76 and the length of the amplified fragments ranged from 150 to 2 500 bp. The POPGENE analysis results showed that the number of polymorphic loci of 6 populations F. pseudograminearum ranged from 58 to 208 with an average of 124. The percentage of polymorphic loci ranged from 24.79% to 88.89% with an average of 52.92%. The effective number of alleles ranged from 1.1548 to 1.3293 with an average of 1.2584. At geographical population level, Nei’s gene diversity ranged from 0.0897 to 0.2069 with an average of 0.1548 and Shannon’s information index varied from 0.1337 to 0.3257 with an average of 0.2368, indicating that there was a genetic variation between geographic populations of F. pseudograminearum. The Shannon’s information index and Nei’s gene diversity of Northern Henan were highest indicating that the isolates of F. pseudograminearum collected from Northern Henan had the highest genetic diversity. The Shannon’s information index and Nei’s gene diversity of Southern Henan were lowest indicating that the isolates of F. pseudograminearum collected from Southern Henan had the lowest genetic diversity. By analysis of the genetic similarity coefficient, the F. pseudograminearum populations of Northern Henan and Eastern Henan were closest and populations of Southern Henan and Eastern Henan were the farthest. The coefficient of the population genetic differentiation (Gst) among geographical groups was 0.1571, while it reached 0.8429 within the populations indicating more divergent genetic diversity within the populations. The number of migrants per generation between 6 geographical populations was 2.6819, which indicated that genetic information exchange was frequent among the 6 populations. Total gene diversity (Ht) was 0.1837, gene diversity within populations (Hs) was 0.1548, and gene diversity between populations (Dst) was 0.0289, which indicated that the isolates collected from the same region showed a relatively close genetic relationship. The dendrogram based on ISSR markers revealed that 6 geographical populations were clustered into two groups at the threshold of a genetically similar coefficient of 0.966. The group Ⅰ included Northern Henan, Eastern Henan, Middle of Henan, Middle of Hebei, and Western Henan, while Southern Henan belongs to group II.  【Conclusion】The genetic variation of F. pseudograminearum collected from Henan and Hebei winter wheat regions was relevant to its geographic distribution. The genetic diversity of F. pseudograminearum among the populations was lower than that within populations. The gene flow of 6 populations of F. pseudograminearum causing crown rot was very frequent.
    Analysis of Microsatellite Loci from Panonychus citri Based on Enriched Microsatellite Library and Transcriptome Dataset
    WEI Dan-dan, LIU Yan, DU Yang, LI Gang, LI Ting, YUAN Ming-long, WANG Jin-jun
    Scientia Agricultura Sinica. 2016, 49(2):  282-293.  doi:10.3864/j.issn.0578-1752.2016.02.009
    Abstract ( 355 )   HTML ( 1 )   PDF (1550KB) ( 588 )   Save
    References | Related Articles | Metrics
    【Objective】 The objective of this study is to construct the microsatellite-enriched libraries, and identify genomic- microsatellite (gSSR) from the genome of the citrus red mite, Panonychus citri. Meanwhile, a large number of gene-microsatellite (EST-SSR) markers were also indentified from the transcriptome database of P. citri. Based on these SSR sequences, the selected SSR primer pairs were validated.【Method】On the basis of isolating high quality genomic DNA of P. citri, enriched microsatellite libraries were constructed by streptavidin-coated magnetic beads utilizing methodologies that exploit the strong affinity between biotin and the protein streptavidin. A fast and easy protocol was proposed through a combination of two different published methods. Briefly, genomic DNA was digested by the restriction enzyme and then ligated to designed adaptors. Microsatellite-containing DNA fragments were captured by streptavidin-coated magnetic beads. The beads affinity capture of microsatellite repeats using biotinylated oligonucleotide probes. Subsequently, PCR was used to amplify the captured molecules for transferring single strand DNA to double strand DNA. The PCR products were then ligated to pGEM-T Easy vector and transformed into Trans5α competent cells. Then, clones from these libraries were screened for microsatellite content. Meanwhile, msatcommander software and bioinformatics methods were used to identify and assess of the quality and quantity of EST-SSR loci from P. citri transcriptome dataset. Primer Premier 5 was used to design P. citri SSR primers, and then these primer pairs were verified by PCR.【Result】Three microsatellite-enriched libraries of AC-repeat, TC-repeat, and ATG-repeat were constructed for P. citri. The positive clone rates of these three libraries were about 30%, 28% and 25%, respectively. The sequencing results showed that the AC library had the highest redundancy rate, and the TC library followed. However, the same clone of SSR in the ATG library was not found. Intriguingly, in the AC library, some AC-repeat types of SSRs existed in many copies with similar or almost identical sequences in one of the flanking regions. Totally, 44 unique microsatellite loci (GenBank number JF776418-JF776461) were obtained. Among these SSRs, 20 primer pairs were synthesized, and 11 primer pairs could be steadily amplified. In gSSR, perfect SSR accounted for 54.5%, and imperfect perfected and compound SSR accounted for 27.3% and 18.2%, respectively. In perfect gSSR, the repeat times (13-42 times) of the di-nucleotide repeat SSR were much higher than tri-nucleotide repeat SSR (5-9 times). A total of 8 023 EST-SSR loci were identified from P. citri transcriptome, and 2 540 SSR sequences could be used for primer design. A total of 35 primer pairs were synthesized (GenBank number KT261306-KT261340), and 8 primer pairs could be steadily amplified. The average distribution distance of the transcriptomic SSRs was 3.55 kb. Tri-nucleotide repeat SSR was the most frequently occurring type in P. citri EST-SSR (53.86%), and di-nucleotide repeat SSR was followed (43.36%). The tetra-, penta-, hexa- nucleotide repeat and compound SSR were very scarce with similar numbers, and accounted for 2.78% in total. The repeat of times of the EST-SSR motifs were mainly concentrated in 5-10 times.【Conclusion】Microsatellite enrichment by magnetic beads is a suitable method to obtain genomic-microsatellite for the P. citri. DNA digestion and ligation were performed simultaneously, which can enhance the concentration of enzyme-digested products and the efficiency of microsatellite enrichment for the mite or small size insects. In P. citri, the repeat times of the gSSR were much higher than that in transcriptomic SSR. In general, the tri-nucleotide repeat SSR will be more suitable for the study of population genetic structure of P. citri. In addition, gSSR have microsatellite DNA families, which indicated that the microsatellite sequences exist in multiple copies in the genome of P. citri.
    SOIL & FERTILIZER·WATER-SAVING IRRIGATION·AGROECOLOGY & ENVIRONMENT
    Effects of Long Term Application of Urea on Ammonia Oxidizing Archaea Community in Black Soil in Northeast China
    ZHOU Jing, JIANG Xin, ZHOU Bao-ku, MA Ming-chao, GUAN Da-wei, ZHAO Bai-suo, CHEN San-feng, LI Jun
    Scientia Agricultura Sinica. 2016, 49(2):  294-304.  doi:10.3864/j.issn.0578-1752.2016.02.010
    Abstract ( 446 )   HTML ( 8 )   PDF (1534KB) ( 960 )   Save
    References | Related Articles | Metrics
    【Objective】 This paper aimed to investigate the characteristics of ammonia oxidizing archaeal (AOA) communities in black soil under long-term fertilization in Northeast China to identify the effects of different doses of urea on the abundance and structure of the AOA community. Combined with the soil physiochemical characteristics, the main driving factors would be revealed. This study provides evidence for further understanding of the nitrification process and mechanism in black soil and enhanced fertilization method.【Method】Based on a 34 year fertilization experiment in Heilongjiang Academy of Agricultural Sciences, three groups of samples were selected with different fertilization including samples without urea (without fertilizer CK and phosphorus-potassium PK), samples with one-time urea (one time nitrogen N1, nitrogen-phosphorus NP, nitrogen-phosphorus- potassium NPK and nitrogen-potassium NK) and samples with two-time urea (two time nitrogen N2). We applied 454 pyrosequencing and quantitative PCR of the Arch-amoA gene to analyze the effects of urea on the AOA communities in black soil. A correlation analysis was carried out to reveal the main important factors for determining the AOA community composition. 【Result】It was found that AOA Arch-amoA copy numbers in black soil were obviously reduced from 2.64×107 to 8.34×105 /g soil along with the increase of the urea amount, and pH in black soil was the direct reason for the decrease of the Arch-amoA gene. Both clustering and Nonmetric Multidimensional Scaling (NMDS) analyzed result proved that the AOA community structure in each fertilizer treatment with the same urea inputs was similar with each other, while the AOA community structure in fertilizer treatments with different urea addition was significantly different with each other. And a redundancy analysis indicated that soil pH, concentration of water soluble organic carbon and nitrate were the main environmental factors (P < 0.05) affecting the AOA community variation. What’s more, phylogenetic analysis demonstrated that the AOA in black soil in the Northeast of China belonged two categories Nitrososphaera and Nitrosotalea, 99.3% of Arch-amoA sequences in fertilizer treatment without urea and 90.1% of Arch-amoA sequences in fertilizer treatment with one-time urea addition belonged to Nitrososphaera, and 67.9% of Arch-amoA sequences with two-time urea addition belonged to Nitrosotalea.【Conclusion】Our research demonstrated the effects of long-term different fertilization on the ammonia oxidizing archaea community, and found out important factors for determining bacterial structures. AOA Arch-amoA copy numbers and communities in black soil with long term urea addition were strongly affected by different doses of urea. AOA diversity in one-time urea treatments increased while that in two-time urea treatment decreased. It is concluded that soil pH, water soluble organic carbon and nitrate nitrogen concentration were the main factors affecting AOA community variation. The results may be greatly meaningful to the rational utilization of fertilizer and agricultural sustainable development.
    Research Advance of High-Yielding and High Efficiency in Resource Use and Improving Grain Quality of Rice Plants Under Water and Nitrogen Managements in an Irrigated Region
    HE Hai-bing, YANG Ru, LIAO Jiang, WU Li-quan, KONG Ling-cong, HUANG Yi-de
    Scientia Agricultura Sinica. 2016, 49(2):  305-318.  doi:10.3864/j.issn.0578-1752.2016.02.011
    Abstract ( 450 )   HTML ( 5 )   PDF (449KB) ( 1162 )   Save
    References | Related Articles | Metrics
    Rice production, especially of good quality, must be increased to feed the world’s growing population in the future. Meanwhile, water scarcity and nitrogen over-fertilization is threatening rice production of irrigated region because of fresh water and fertilizer nitrogen crises. Therefore, a major challenge in rice production is to save both water and fertilizer nitrogen while increasing grain yield and improving quality characteristics. Rice production must synchronously focus on high grain yield and good-quality when rice is planted under both water and nitrogen saving cultivation. In brief, rice production and sustainable development are considered not only for high yield and good quality, but also to ensure high water/nitrogen use efficiencies. Based on this background, the paper reviews (1) the effect of water regimes, nitrogen managements, and water-nitrogen interaction managements on grain yield, water/nitrogen use efficiencies, and grain quality of rice plants, respectively; (2) eco-physiological mechanisms obtaining high-yielding and good quality with high water/nitrogen use efficiencies when irrigated rice plants are managed in different water treatments, nitrogen treatments, and water-nitrogen interaction treatments. Finally, some potential research points including theory and technology researches, which could increase yield and improve quality of rice plants with high resources (water and nitrogen ) use efficiencies, were presented in this review.
    HORTICULTURE
    Effect of Phosphorus Levels on Growth, Morphological Characteristics and Leaf Element Contents of Juglans sigillata Dode Seedlings
    ZANG Cheng-feng, FAN Wei-guo, PAN Xue-jun
    Scientia Agricultura Sinica. 2016, 49(2):  319-330.  doi:10.3864/j.issn.0578-1752.2016.02.012
    Abstract ( 424 )   HTML ( 2 )   PDF (3824KB) ( 454 )   Save
    References | Related Articles | Metrics
    【Objective】The objective of this study was to explore the effect of different phosphorus levels on the growth, morphological characteristics and element absorption of Juglans sigillata Dode seedlings, and provide a scientific foundation for the determination of soil phosphorus diagnostic criteria and phosphorus application for young trees.【Method】Using Juglans sigillata Dode seedlings as materials, the metamorphic rocks of acid yellow soil parent material development for cultivating soil,the soil culture experiments were employed to study the effect of different phosphorus levels on the growth, biomass, root-shoot ratio, root morphology characteristics and leaf element contents. 【Result】 Under the condition of 5, 25, 45, 65, 85, 105 and 125 mg·kg-1 effective phosphorus levels, the plant total biomass, root and shoot biomass decreased when the phosphorus nutrition level was lower than 45 mg·L-1 or higher than 45 mg·L-1. Under the condition of 45 mg·kg-1 phosphorus nutrition level, the root development of Juglans sigillata Dode root was the best and the plant of fresh and dry weight reached maximum, 183.07 g/plant and 109.84 g/plant. Under the condition of 125 mg·kg-1 phosphorus nutrition level , root system growth was the worst and plant total biomass was the minimum, only 66.93 g/plant and 40.16 g/plant. Phosphorus levels higher than 45 mg·kg-1, with the increase of the phosphorus levels on plant growth inhibition enhanced obviously, the inhibitory effect was more obvious than the low phosphorus treatment. The root-shoot ratio of the plant with 5 mg·kg-1 phosphorus processing one of the biggest was 1.34, with 45 mg·kg-1 deal with the minimum of only 1.07. In the 5, 25 and 45 mg·kg-1 of phosphorus processing , with the increase of phosphorus levels of the plant height, aboveground base diameter, total leaf area, root length, total surface area, root volume, root average diameter, total root number, root fractal dimension number, root length, lateral root length, lateral root number, whole plant root length density and root mass density increased obviously, the above index of phosphorus levels higher than 45 mg·kg-1 processing decreased significantly, with 125 mg·kg-1 phosphorus levels to a minimum. With the phosphorus nutrition level increasing, the elements content of P, Ca, Mg, Mn and Cu increased. With the increase of phosphorus levels leaf N, K, Fe, Zn, and B content and phosphorus supply was on a first increasing and then decreasing trend. When the phosphorus nutrition level was extremely lower or higher than 45 mg·kg-1, the contents of P, Mg, Mn and Cu would be deficient or excessively accumulative. When phosphate levels were higher or lower than 45 mg·kg-1, the absorption of N, K, Fe, Zn, and B elements was significantly lower.【Conclusion】In the metamorphic rock the parent material development of acid yellow soil, the condition of soil phosphorus levels that reached about 45 mg·kg-1 was most conducive to Juglans sigillata Dode seedlings growth and uptake of nutrient elements, obviously improved root morphological characteristics, phosphorus levels too low or too high had obvious inhibitory effects on the growth of the plant root system and above ground growth, high phosphorus levels had an adverse effect on plant growth and was more obvious than the low phosphorus condition.
    STORAGE·FRESH-KEEPING·PROCESSING
    In?uence of Barley-Based Diets on Physico-Chemical Characteristics and Fatty Acid Composition of Dry-Cured Ham Produced with Dahe Black Pig’s Hind Leg
    ZHANG Ting, WANG Zhen-yu, LI Zheng, LIN Zu-song, LI Xiang, TIAN Jian-wen, ZHANG De-quan
    Scientia Agricultura Sinica. 2016, 49(2):  331-338.  doi:10.3864/j.issn.0578-1752.2016.02.013
    Abstract ( 502 )   HTML ( 2 )   PDF (400KB) ( 395 )   Save
    References | Related Articles | Metrics
    【Objective】The aim of the study was to investigate the influence of barley-based diets on the physico-chemical characteristics and fatty acid profile of dry-cured ham produced with Dahe black pig’s hind legs, and supply elementary data for the Dahe black pig breeding management and meat products’ processing. 【Method】Landrance × Dahe black crossed piglets fed with barely and corn (as a control ), were slaughtered at 100 (180 days), 130 (210 days) and 160 kg (250 days) lived body weight, and processed into dry-cured hams with their hind legs according to the traditional processing and adding 8% sodium chloride. The salt, protein, water, intramuscular lipid content, fatty acids, lipid oxidation and protein oxidation of the hams were determined. 【Result】Compared with corn-based diets, the Dahe black pigs’ (100, 130, 160 kg live body weight) dry-cured hams of barley-based diets had 2%-4% higher protein content and 2%-4% lower fat content. The salt content of dry-cured hams from Dahe black pigs (160 kg live body weight) fed with barley was 1.03% lower than corn-based diets’ hams, and the water content was 4.52% higher than corn-based diets’ hams. Monounsaturated fatty acids and polyunsaturated fatty acids of 130 kg group fed with barley were highest in all groups, and the highest saturated fatty acids in 160 kg corn fed group. After being fed with barley, the palmitic acids of 100 kg group and 130 kg group decreased significantly (P<0.05), stearic acids of 130 kg group and 160 kg group were lowered (P<0.05). With live weight growth, carbonyl content of dry-cured hams firstly increased and then was stable. The carbonyl content in barley diet groups was much lower than corn diet groups. The TBARS was not significant between barley diet groups, and the TBARS of 130 kg group was significantly lower than 100 kg group and 160 kg group (P<0.05). Furthermore, the dry-cured hams of barley-based diets tend to show lower extent of the lipid and protein oxidation than corn-based diets. The Dahe black pigs’ hams of barley-based diets had a higher content of polyunsaturated fatty acids and the ration of PUFA/SFA than corn-based diets (P<0.05). The quality of dry-cured hams produced with hind legs of Dahe black pigs (160 kg) fed with barley was the best, that was, the content of salt, water, protein, fat, PUFA and PUFA/SFA, n-6/n-3, carbonyl content and TBARS value were 7.96%, 48.3%, 34.64%, 8.52%, 12.18%, 0.31, 30.25, 0.62 nmol·mg-1 protein and 2.14 mg·kg-1, respectively. 【Conclusion】It was concluded that the protein and poly-unsaturated fatty acids content increased and the oxidized stability was enhanced, being produced by hind legs of Dahe black pigs fed with some barley.
    ANIMAL SCIENCE·VETERINARY SCIENCERE·SOURCE INSECT
    Stock Capacity in Different Cropping Systems
    YANG Jun-xiang, WANG He-liang, JIAO Hong-chao, LIN Hai
    Scientia Agricultura Sinica. 2016, 49(2):  339-347.  doi:10.3864/j.issn.0578-1752.2016.02.014
    Abstract ( 393 )   HTML ( 1 )   PDF (365KB) ( 863 )   Save
    References | Related Articles | Metrics
    【Objective】The rapid development of intensive animal production in China caused the problem of effective disposal and usage of manure and waste water, which is a great challenge on surrounding environment. The aim of the present study is to determine the stock capacity in different cropping systems.【Method】The pig production, swine manure production, and manure nitrogen and phosphorus emission in Shandong province were calculated. The nitrogen and phosphorus requirements under three cropping systems, wheat-corn production, apple production, and vegetable production (three kinds of greenhouse cultivation modes: bell pepper-eggplant, bell pepper-tomato and tomato-cucumber; three open field cultivation modes: eggplant-Chinese cabbage, tomato- Chinese cabbage, cucumber-radish), were estimated as well. A mathematical model was built to determine the stock capacity based on the principle of ecological balance. 【Result】 Hog unit was used to estimate the nitrogen and phosphorus emission content in a pig farm. A hog unit was defined as the total amount of nitrogen or phosphorus in manure from all types of pigs in a pig farm expressed on the basis of breeding sows. A hog unit equaled 87.5kg N/year and 11.1kg P/year. The output of nitrogen and phosphorus from farmland was estimated in three cropping systems. The result showed that the vegetable cultivation system had higher nitrogen and phosphorus outputs while the apple production system had lower nitrogen and phosphorus outputs, compared to grain production system. For vegetable cultivation, the stock capacities under greenhouse and open-field production patterns were 4.5 and 3.8 hog unit/hm2, respectively. The stock capacity in apple production system was 1.2 hog unit/hm2. In grain production, the stock capacity was dependent on the straw returning to field and the suitable stock capacity for wheat/maize production system was 3.9 hog unit/hm2 in case of no straw returning to field. The minimum farmland needed for the effective usage of animal manure produced from a pig farm of 1000 breeding sow was 188.7, 833.3, and 256.4 hm2 under vegetable, apple, and grain production systems, respectively. 【Conclusion】 In the recycling ecological model of animal husbandry-cropping system, the suitable stock capacity was from 1.2 to 4.5 hog unit/hm2, based on different cultivating systems. The present result has laid a foundation for the regional planning of animal husbandry and manure and farmland management.
    Identification of Candidate Genes for Hematological Traits by Integrating Gene Expression Profiling and Genome-Wide Association Study in a Porcine Model
    XU Pan, ZHANG Zhen, ZHANG Feng, YANG Bin, DUAN Yan-yu
    Scientia Agricultura Sinica. 2016, 49(2):  348-360.  doi:10.3864/j.issn.0578-1752.2016.02.015
    Abstract ( 437 )   HTML ( 7 )   PDF (2848KB) ( 1078 )   Save
    References | Related Articles | Metrics
    【Objective】We herein integrated digital gene expression profiling and genome-wide association study in a White Duroc × Erhualian F2 resource population to identify candidate genes for hematological traits.【Method】The White Duroc × Erhualian F2 resource population were slaughtered at 240 ± 3 days. Blood was collected in anticoagulation tubes. A set of hematological parameters were measured using a whole blood analyzer. The 1 020 F2 pigs were genotyped using an Illumina porcine 60K SNP chip. Individuals with genotype-missing rates > 10% and Mendellian errors > 5% were removed. SNPs with a call rate < 95%, minor allele frequency < 5%, P value < 5 × 10-6 for Hardy Weinberg equilibrium (HWE), and the autosomal SNPs that were linked to sex chromosome were excluded. The liver samples of the 502 F2 pigs were then performed digital gene expression profiles sequencing on Illumina GA II. The raw tags were filtered to obtain clean tags. The clean tags were uniquely mapped to the reference gene sequences and were defined as unambiguous clean tags. The number of unambiguous clean tags was normalized to represent the expression level of each transcript. The expression level of each transcript was further transformed to lg2 value. The transcripts that expressed less than 20% of individuals were rejected. The traits of phenotype and gene expression were adjusted for sex, batch and kinship using polygentic function of GenABEL in R package. The correlations between gene expressions and phenotypic traits were evaluated using the residuals by Spearman’s correlation coefficient with a conservative threshold P < 0.0005. Positions of detected eQTL were plotted against the positions of the genes for which that eQTL were found. We also searched the eQTL within the 5.0 Mb region of the peak SNP of GWAS and performed an integrated analysis of eQTL and GWAS. Gene Ontology & KEGG pathway enrichment analysis was implemented by DAVID online tools and gene co-expression network was constructed by GeneMANIA online tools. 【Result】A total of 20 108 liver transcripts of 502 F2 pigs achieved the quality control requirements. We obtained 259 transcripts strongly associated with hemoglobin (HGB), red blood cell count (RBC), hematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and white blood cell count (WBC) respectively with a conservative threshold P < 0.0005. 34 liver transcripts were significantly associated with two or more phenotypic traits. Three hundred and four loci (eQTL) were identified to affect the transcription levels of these genes including 35 cis-eQTL and 120 trans-eQTL with P < 10-5. Each transcript was mapped to one to six eQTL. MCH and MCV shared the same cis-eQTL located on SSC8. The largest number of eQTL were located on SSC7 and most of them were trans-eQTL. KIT was identified as a candidate gene by eQTL analysis. Gene Ontology & KEGG pathway enrichment analysis allowed us to prioritize five candidate genes such as for KIT, PSEN2,and TFRC for RBC and THBS1, CYR61 for WBC. RPS10 was also identified as the candidate gene for WBC by the integration of eQTL, GWAS and gene co-expression network. 【Conclusion】In this study, we identified KIT, PSEN2,TFRC as the candidate genes for RBC, THBS1, CYR61, RPS10 as the candidate genes for WBC by integrating gene expression profiling and genome-wide association study in the White Duroc × Erhualian F2 resource population.
    Correlation of the Relative Levels of Insulin-Like Growth Factor - I and Myostatin mRNA Expression and Asynchronous Development of Skeletal Muscles Development in Ducks During Early Development
    HU Yan, LIU Hong-xiang, SHAN Yan-ju, JI Gai-ge, SHU Jing-ting, XU Wen-juan, ZHU Chun-hong, TAO Zhi-yun, LI Hui-fang
    Scientia Agricultura Sinica. 2016, 49(2):  361-370.  doi:10.3864/j.issn.0578-1752.2016.02.016
    Abstract ( 331 )   HTML ( 2 )   PDF (383KB) ( 688 )   Save
    References | Related Articles | Metrics
    Objective The present experiment was conducted to study the mRNA expression characterization of insulin-like growth factor 1 (IGF-I) and myostatin A (MSTN-A), thedevelopmental pattern in duck skeletal muscles and their correlation during embryogenesis and post-hatching development in different breeds of ducks. MethodWe have compared the ontogeny of body weight, the weight of pectoralis major (PM) and lateral gastrocnemius muscle (LM) and the mRNA expression of insulin-like growth factor-I (IGF-I) and myostatin A (MSTN-A) at the embryonic days 13, 17, 21, 25, 27 and the neonatal age of 7 days of Gaoyou duck and Jinding duck. ResultDuring embryogenesis and post-hatching development, the weight of PM and LM showed an extreme significant difference by duck variety and time. The mRNA expression of IGF-I and MSTN-A in duck breast/leg muscles had significantly negative correlations with body weight and weight of skeletal muscle, but had a positive correlation with breast/leg muscles index. During early development, there were extremely significant positive correlations between the mRNA expression of IGF-I and MSTN-A, and there were peaks in the mRNA expression of IGF-I and MSTN-A at embryonic age of 13 days. The turning points of IGF-I mRNA expression in duck PM were matched with PM growth, and but not for LM. During duck myogenesis, the profile of MSTN-A expression showed synchronization with growth of skeletal muscle and the peaks of proliferation in changes of myofiber characters, and the differences of the IGF-I/MSTN-A mRNA ratio in PM between the two myoblasts. The IGF-I/MSTN-A mRNA ratio in PM and LM were significantly higher with a similar trend in the breeds matched the timing of varieties difference in PM weight. Conclusion During embryogenesis and post-hatching development, the duck PM and LM developed in an asynchronous pattern. The relative levels of IGF-I and MSTN mRNA may participate to set muscle growth rate along development.
    Cloning, Antibody Preparation and Subcelluar Localization of BmGATA6 in Silkworm (Bombyx mori)
    TAN Peng, XU Man, LIANG Hang-hua, ZHANG Ya-jun, HU Ren-jian, CUI Hong-juan
    Scientia Agricultura Sinica. 2016, 49(2):  371-380.  doi:10.3864/j.issn.0578-1752.2016.02.017
    Abstract ( 298 )   HTML ( 2 )   PDF (1907KB) ( 418 )   Save
    References | Related Articles | Metrics
    【Objective】The objective of this study is to clone and overexpress BmGATA6 in Escherichia coli to obtain the recombinant protein, which can be used to immunize mice for the preparation of polyclonal anti-BmGATA6 antibody. And to provide a theoretical basis for further studying the function of BmGATA6 in silkworm (Bombyx mori). 【Method】B. mori was killed to obtain the different tissues on day 3 of 5th instar larvae and the midguts from the molting period of the 4th instar larvae to the wandering stage, and these tissues were grinded into powder in the liquid nitrogen. Tissue RNA was extracted by Trizol, and cDNA was reversely transcribed in vitro. The full-length specific primer sequences were designed according to BmGATA6 coding sequence. Using BmActin3 as a reference gene, RT-PCR was conducted to detect the expression of BmGATA6 both in the different tissues on day 3 of 5th instar larvae and the midguts from the molting period of the 4th instar larvae to the wandering stage. The prokaryotic expression primer sequences were designed, and the amplified fragment was ligated to the pET32a, which was then transformed into BL21 (DE3) E. coil to obtained fusion protein. The recombinant BmGATA6 protein was induced with 0, 0.4, 0.6, 0.8 and 1.0 mmol·L-1 IPTG for 20 h at 16℃ or 5 h at 37℃. The optimal induction conditions were chosen to gain BmGATA6 protein, and Ni-NTA affinity chromatography was utilized to purify the BmGATA6 protein. Then the anti-BmGATA6 polyclonal antibody was obtained after immunizing mice with recombinant protein. The expression of BmGATA6 was detected by Western blot with the antibody, which was identified by ELISA. Taking paraffin sections of the midgut on day 6 of 5th instar larvae as samples, the subcellular localization of BmGATA6 protein in the midgut of B. mori was conducted by immunofluorescence.【Result】The cDNA of BmGATA6 was 4 011 bp. The ORF of BmGATA6 was 1 974 bp, encoding 657 amino acids. The cDNA of BmGATA6 was comprised of 205 bp 5′UTR and the 1 832 bp 3′UTR. BmGATA6 was located on chromosome 15 in B. mori genome, and the full-length was 12 326 bp. BmGATA6 was a gene with multiple exons structure, including 8 exons and 7 introns. The predicted protein sequence contained two conserved zinc-finger domains, which were located in 470-521 and 531-582 amino acid regions. RT-PCR results showed that the BmGATA6 was highly expressed in the midguts on day 3 of 5th instar larvae, while the expression was low in the Malpighian tubule, and no BmGATA6 expression was detected in other tissues. Besides, RT-PCR results showed that the BmGATA6 was continually expressed in midguts from the molting period of the 4th instar larvae to the wandering stage. Construction of prokaryotic expression vector of BmGATA6, it was found that the recombinant BmGATA6 protein mainly existed in the supernatant at 16℃, or in inclusion bodies at 37℃. The recombinant BmGATA6 protein was best induced with 0.6 mmol·L-1 IPTG for 20 h at 16℃, then purified using Ni-NTA affinity chromatography. To obtain the anti-BmGATA6 polyclonal antibody, mice was immunized repeatedly with pure protein. ELISA indicated that BmGATA6 antibody titer was 1﹕128 000. Western blot demonstrated that anti-BmGATA6 polyclonal antibody, which was prepared by ourself, could detect BmGATA6 protein specifically. BmGATA6 protein molecular weight was about 75 kD, consistent with prediction. Immunofluorescence results showed that BmGATA6 was highly expressed in midgut cells of B. mori, and it was located in nucleus.【Conclusion】Anti-BmGATA6 polyclonal antibody was prepared successfully, and preliminary analysis of its subcellular localization in the midgut tissue was done, which revealed that BmGATA6 played an important role in the regulation of physiological changes in the midgut of B. mori, and laid the foundation for further exploration of the BmGATA6 function in B. mori.
    RESEARCH NOTES
    Cloning and Expression of Poncirus Trifoliata (L.) Raf. NIN- Like Transcription Factors under Different Water Conditions
    CAO Xiong-jun, LU Xiao-peng, XIONG Jiang, LI Jing, WU Qian, ZHOU Fang-fang, XIE Shen-xi
    Scientia Agricultura Sinica. 2016, 49(2):  381-390.  doi:10.3864/j.issn.0578-1752.2016.02.018
    Abstract ( 339 )   HTML ( 2 )   PDF (5502KB) ( 647 )   Save
    References | Related Articles | Metrics
    【Objective】The objective of this study was to analyze the expression of Poncirus trifoliata (L.) Raf. NIN-like transcription factors to discuss the regulation mechanism of nitrogen assimilation under different water conditions in citrus.【Method】 Primers were designed to amplify the sequences of the NLP genes CDS of Poncirus trifoliate (L.) Raf.based on orange genome databases and molecular biology. Alignment of the sequences was performed using ClustalX and phylogenetic analysis of this alignment was conducted using MEGA. Analysis of the Relative NLP genes expression data under different water conditions using Real-Time Quantitative PCR.【Result】Four Poncirus trifoliata (L.) Raf. NLP genes: PtNLP2, PtNLP4, PtNLP7 and PtNLP8 were obtained. The sequence alignment analysis showed that the identity of all NIN-like proteins was 45.13%, and possessed both the RWP-RK and PB1 domain, and all NIN-like proteins were high identity to sweet orange, respectively 97.57%, 96.47%, 99% and 97.33%. Phylogenic analysis has indicated that the 4 Poncirus trifoliata (L.) Raf. NLP genes can be classified into four groups with Arabidopsis (PtNLP2 and AtNLP1/2, PtNLP4 and AtNLP4/5, PtNLP7 and AtNLP6/7, PtNLP8 and AtNLP8/9). There were differences in the expression pattern of NLP genes in Poncirus trifoliata (L.) Raf. leaves and roots. The results indicated that with the decrease of soil water, the expression level of NLP genes in Poncirus trifoliata (L.) Raf. leaves were up-regulated. The PtNLP2, PtNLP4, PtNLP7 and PtNLP8 expression level were the highest when the relative water capacity was 15.4%, they were 2.9, 3.5, 5.9 and 2.8 folds higher respectively compared to the control (the relative water holding capacity was 61.0%). After that, the gene expression level began to down-regulate and had no statistically significant difference between the control and the relative water holding capacity of 9.4%. While the expression level of NLP genes in Poncirus trifoliata (L.) Raf. roots of control were the highest, and the gene expression pattern showed a down-regulated trend accompanied by the loss of soil water and the difference was statistically significant. The PtNLP2, PtNLP4, PtNLP7 and PtNLP8 expression level of roots were maximum down-regulated by 6.7, 2.8, 4.8 and 2.3 folds respectively compared with the control. The expression of NLP genes in Poncirus trifoliata (L.) Raf. leaves and roots remained at the low expression level after rewatering and had statistically significant difference compared with the control.【Conclusion】The expression of Poncirus trifoliata (L.) Raf. NLP genes is closely related to the water condition of soil. The expression level of NLP genes in Poncirus trifoliata (L.) Raf. leaves were up-regulated by drought stress, and then down-regulated when the water deficit was very serious. But the expression level of NLP genes in Poncirus trifoliata (L.) Raf. roots were down-regulated continuously accompanied by the loss of soil water, and expression of the PtNLP2 and PtNLP7 had a great change in roots.
    Nitrogen Release Characteristics of Compound Fertilizers with Different Manufacturing Processes and Their Effect on Maize Yield
    HUANG Xing-cheng, LIU Yu-hong, ZHANG Yu-ting, ZHAO Ya-nan, ZHANG Yue-qiang, SHI Xiao-jun
    Scientia Agricultura Sinica. 2016, 49(2):  391-398.  doi:10.3864/j.issn.0578-1752.2016.02.019
    Abstract ( 383 )   HTML ( 2 )   PDF (23390KB) ( 434 )   Save
    References | Related Articles | Metrics
    【Objective】 Many kinds of manufacturing processes for compound fertilizer production exist and result in substantial differences in fertilizer properties. By clarifying the difference of compound fertilizers with different processes on crop yield and nutrient use efficiency, it would be useful for both producing and using of compound fertilizers.【Method】Six kinds of nutrient-equal compound fertilizers (N-P2O5-K2O, 15-15-15) with different manufacturing processes were collected to study their N release characteristics in an incubation experiment and then their effects on maize yield, N uptake and N use efficiency in field experiment. 【Result】 Nitrogen release curves of these compound fertilizers showed parabolic shapes and could be fitted by Richards equation. Whereas the accumulative release rate and maximum release rate of N in compound fertilizers varied greatly due to manufacturing processes, both following an decreasing order by processes of blending (BL), agglomeration process (AG), spraying granulation (SG), AZF, tower granulation (TG) and urea formaldehyde (UF), respectively. Compared with BL processed fertilizer in a field trial, AZF, TG and UF processed fertilizers resulted in higher N accumulation and finally increased the maize yield by 5.1%, 5.7% and 8.8%, respectively. In relative to yield component, AZF, TG and UF processed fertilizers increased kernel number per cob by 10.2%, 13.5% and 15.6% than that of BL processed fertilizer, respectively. Maize yield showed a significant and positive relationship with kernel number per cob with coefficient of 0.96 (P<0.01); furthermore, both of them showed significant correlation with shoot N accumulation at 50 days after planting. This indicated that higher N accumulation during the vegetative growth stage enhanced ear development and thereafter increased maize grain yield. In addition, N use efficiency of maize indicated by apparent recovery efficiency, partial factor productivity, agronomic efficiency and fertilizer contribution to yield, was also improved by treatments with the UF, TG and AZF processed fertilizers than that with BL processed fertilizer.【Conclusion】Compound fertilizers with improved manufacturing processes and raw materials had a slower release characteristics of N, which contributed to more N accumulation in early vegetative stage, improved growth and cob development, and thus increased maize yield and N use efficiency.
    The Yield, Nutritional Value and Silage Quality of Three Wheat Varieties Planted on the Winter Fallow Field
    LI Chun-jiang, XU Zhao-hong, SHI Qing-ping, QIN Tian-tian, DONG Zhao-xia, ZHANG Jian-guo
    Scientia Agricultura Sinica. 2016, 49(2):  399-406.  doi:10.3864/j.issn.0578-1752.2016.02.020
    Abstract ( 422 )   HTML ( 1 )   PDF (449KB) ( 471 )   Save
    References | Related Articles | Metrics
    【Objective】The whole-crop wheat (Triticum aestivum L.) has been used as forage for a long time in some countries. However, there were few studies and no forage wheat was bred in China. The present research compared the yields, nutrient value and fermentation quality of 3 wheat varieties selected from 15 varieties before, in order to provide a theoretical basis for planting wheat on winter fallow fields in South China. 【Method】Wheat was sown after autumn rice was harvested. The  seedling density of three varieties was 3.3×105 plants·hm-2 with three replicates in a randomized block design, and the area of each plot was12 m2(3 m×4 m). The N, P2O5 and K2O were applied with 90.0, 36.0 and 48.0 kg·hm-2 at a ratio of 6 to 4 as base fertilizer to topdressing at jointing stage. At dough stage, the plant height, tiller number of wheat were observed, and the yield was determined using a quadrant of 1.0 m×1.0 m in triplicates; the plant materials above 10 cm of the ground were taken for  microbiological analysis. The fresh samples were taken for chemical analyses and silage making. Fresh wheat materials were chopped into 2 to 3 cm lengths. After thorough mixing, 300 g of fresh materials was immediately packed into a plastic film bag (30 cm × 40 cm) in triplicates, degassed and sealed using a vacuum sealer. Thereafter, the bags were maintained at dark place for 60 d at the ambient temperature for silage quality investigation. The dried materials were ground by a hammer mill for chemical analyses.【Result】The plant heightand yields of dry matter and crude protein of Shimai 001 were 75.27 cm, 6.69 and 0.53 t·hm-2, respectively, significantly higher than the other two varieties (P<0.05); the dry matter digestibility and relative feeding value of HYN were the highest (63.84% DM and 113.51). The crude protein content of Xumai 856 was higher than that of HYN (P<0.05), while Shimai 001 had no significant differences with the former varieties. The soluble carbohydrates contents of HYN, Shimai 001 and Xumai 856 were 11.83% DM, 9.14% DM and 5.93% DM, respectively, which were significantly different (P<0.05). There were no significant differences in amounts of lactic acid bacteria, aerobic bacteria, yeasts and molds among wheat varieties (P>0.05). More lactic acid bacteria epiphyted on 3 varieties, which exceeded 106 cfu·g-1 FM. After opening the bag silos, the pH values of Shimai 001 and HYN were about 4.30, lower than 4.50 of Xumai 856, but not significant (P>0.05). Shimai 001 had better fermentation quality, indicated by the highest content of lactic acid and the lowest content of butyric acid. After the silage materials were exposed upon to air for 192 h, the pH values of Shimai 001 and Xumai 856 had little change, their aerobic stability was better than that of HYN.【Conclusion】Based upon the yields of dry matter and crude protein, nutritional value and silage quality of whole plant wheat, Shimai 001 has a great potential as forage planting on winter fallow fields in Guangdong province.