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Table of Content

    12 July 2015, Volume 41 Issue 07
    • CROP GENETICS & BREEDING·GERMPLASM RESOURCES·MOLECULAR GENETICS
      Molecular Mapping of a New Yellow Green Leaf Gene YGL9 in Rice (Oryza sativa L.)
      ZHANG Tian-Quan,GUO Shuang,XING Ya-Di,DU Dan,SANG Xian-Chun,LING Ying-Hua,HE Guang-Hua
      Acta Agron Sin. 2015, 41(07):  989-997.  doi:10.3724/SP.J.1006.2015.00989
      Abstract ( 886 )   RICH HTML    PDF (3462KB) ( 1104 )   Save
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      Leaf color mutants are ideal materials in illuminating molecular mechanism of photosynthesis, chlorophyll metabolic pathway and chloroplast development. A novel mutant named yellow green leaf 9 (ygl9) was isolated from the progeny of ethyl methane sulfonate (EMS) treated Jinhui10 (Oryza sativa L. ssp. indica) and displayed yellow-green leaves at the seedling stage while light green at the heading stage. Compared with those of the wild type, the photosynthetic pigments of the ygl9 mutant reduced very significantly before the tillering stages and significantly in the heading stage. However, there was no obvious changing for net photosynthetic rate between the wild type and the mutant. The characteristics of stomata length, stomatal conductance and transpiration rate increased significantly in the ygl9. The observation by transmission electron microscope showed that the ygl9 mutant contained comparable chloroplasts with more osmiophilic granules, fuzzy grana and fewer/looser stroma lamella to the wild type. Genetic analysis suggested that the mutational trait was controlled by a single recessive gene. Using 759 mutational individuals from the F2 generation of Xinong 1A/ygl9, the YGL9 locus was finally mapped on the short arm of chromosome 3 between SSR marker S03-1 and InDel marker Ind03-19 with genetic distances of 0.13 cM and 0.07 cM respectively, and the physical distance was only 63 kb. These results provided a foundation for map-based cloning and functional analysis of YGL9 gene.

      Phylogeny of Maize Landraces in Southwestern China Based on Glb 1 Sequences
      YAO Qi-Lun,CHEN Fa-Bo,LIU Hong-Fang,FANG Ping
      Acta Agron Sin. 2015, 41(07):  998-1006.  doi:10.3724/SP.J.1006.2015.00998
      Abstract ( 685 )   RICH HTML    PDF (1682KB) ( 823 )   Save
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      To explore the DNA polymorphism of Glb 1 genes in maize landraces from Southwest China, we cloned and sequenced the DNA sequences from 40 maize landraces, and downloaded the homologous sequences of 19 individuals representing common maize, parviglumis, Z. luxurians, and T. dactyloides from GenBank. By aligning these sequences and analyzing DNA variations in Glb 1 loci, we found 35, 25, 33 and 25 polymorphism sites in maize landraces from Sichuan, Chongqing, Yunnan, and Guizhou, respectively. Their genetic polymorphisms were 87%, 86%, 85%, and 71% of that in parviglumis. On the basis of estimates of  per base pair and  per base pair, the highest level of sequence variation was found in parviglumis, followed in turn by maize landraces from Sichuan, landraces from Chongqing, landraces from Yunnan, landraces from Guizhou, common maize, T. dactyloides, and Z. luxurians. The estimates of Tajima's and Fu and Li’s D statistic for Glb 1 gene were negative in the eight taxa, suggesting that neutrality cannot be rejected. In comparison, more fixed differences than shared polymorphisms between maize landraces and parviglumis, Z. luxurians, as well as T. dactyloides were found. The genealogical and network analysis provided the evidence for the genus Zea taxonomy. Additionally, genetic diversity of landraces was greater in Sichuan than in the other three regions. This result supports the hypothesis that the first maize migration was from India to Sichuan by way of Tibet in China.

      Genetic Dissection of Grain Chalkiness in Indica Mini-core Germplasm Using Genome-wide Association Method
      QIU Xian-Jin,YUAN Zhi-Hua,CHEN Kai,DU Bin,HE Wen-Jing,YANG Long-Wei,XU Jian-Long,XING Dan-Ying,Lü Wen-Kai
      Acta Agron Sin. 2015, 41(07):  1007-1016.  doi:10.3724/SP.J.1006.2015.01007
      Abstract ( 997 )   RICH HTML    PDF (1545KB) ( 1780 )   Save
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      In order to dissect the genetic bases and mine novel alleles of grain chalkiness in indica, we conducted an experiment with  genome-wide association analysis using phenotypic data collected from multiple locations (Sanya of Hainan, Shenzhen of Guangdong, Hangzhou of Zhejiang, and Jingzhou of Hubei) and 6704 re-sequenced SNP markers distributed in whole genome for 272 indica mini-core germplasm collected worldwide. All accessions were classified into three subpopulations based on SNP data. Total of 42 and 44 loci were detected as significant associations with percentage of grains with chalkiness (PGWC) and degree of endosperm chalkiness (DEC), respectively, which distributed all over the 12 chromosomes. Twenty one and nineteen loci were stably expressed for PGWC and DEC in multiple locations, respectively, and 12 simultaneously affected the two traits. Eleven of the said loci were co-located in the same or near regions harboring the quality genes cloned previously. Of them, the region of 3.3–5.3 Mb on chromosome 5 was significantly associated with PGWC at all four locations, having the largest phenotypic contribution detected in Hangzhou location, and the carrier variety with the best favorable allele was IRGC121689; the another region of 17.5–22.7 Mb on chromosome 12 was significantly associated with DEC at Sanya and Hangzhou, having the largest phenotypic contribution detected in Sanya, and the carrier variety with the best favorable allele was IRGC122285. These loci and germplasms are important potential genes and variety resources that can be used in molecular breeding for rice appearance quality.

      Cloning and Functional Analysis of Nonspecific Phospholipase C gene SiNPC4 in Foxtail Millet (Setaria italic)
      HU Li-Qin,XUE Fei-Yang,LI Wei-Wei,WANG Er-Hui,XU Zhao-Shi,LI Lian-Cheng,ZHOU Yong-Bin,JIA Guan-Qing,DIAO Xian-Min,MA You-Zhi,CHEN Ming
      Acta Agron Sin. 2015, 41(07):  1017-1026.  doi:10.3724/SP.J.1006.2015.01017
      Abstract ( 808 )   RICH HTML    PDF (4548KB) ( 1208 )   Save
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      Nonspecific phospholipase C (NPC) catalyzes the hydrolysis of phosphatidylcholine or phosphatidylethanolamine to generate diacylglycerol (DAG), which is an important second messenger in cells. NPC family plays a key role in response to some stresses such as drought, high salinity and phosphorus deficiency, and is involved in some hormone signaling pathways such as abscisic acid (ABA) and brassinolide (BL). Taking foxtail millet as material, we cloned a novel NPC gene named SiNPC4 by sequence alignment. This gene was detected to be located on chromosome 8. The full length of SiNPC4 was 2877 bp with three exons and two introns encoding 512 amino acid residues and the protein molecular weight was 56.77 kD. Phylogenetic analysis of NPC protein sequences indicated that SiNPC4 distributed to the third subfamily. The predicted protein structure of the gene contained conserved phosphoesterase domain and four motifs. The protein subcellular localization analysis revealed that SiNPC4 was localized in cytomembrane, cytoplasm, and nucleus. The gene expression profile results indicated SiNPC4 mainly expressed in root and was induced by drought, salt, cold, dark, ABA, BL, methyl jasmonate (MeJA), and gibberellic acid (GA) treatments. Arabidopsis carrying SiNPC4 decreased the sensitivity to ABA and BL compared with WT. Thus, we deduced that SiNPC4 may act as a negative regulator in ABA and BL signaling pathways. Besides, there were no significant difference in growth between transgenic and wild type plants under drought and high salinity treatments.

      Quantitative Trait Loci Mapping for Plant Height, the First Branch Height, and Branch Number and Possible Candidate Genes Screening in Brassica napus L.
      WANG Jia,JING Ling-Yun,JIAN Hong-Ju,QU Cun-Min,CHEN Li,LI Jia-Na,LIU Lie-Zhao
      Acta Agron Sin. 2015, 41(07):  1027-1038.  doi:10.3724/SP.J.1006.2015.01027
      Abstract ( 772 )   RICH HTML    PDF (1190KB) ( 978 )   Save
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      Plant height, the first branch height and branch number are important agronomic traits in rapeseed. In our study, QTL mapping of plant height, the first branch height and branch number in Brassica napus was tested by using the high density SNP genetic map constructed from the high generation RIL population with the rapeseed 60K chip array. The reference SNP genetic map contains 2795 SNP markers, covering 1832.9 cM with an average distance of 0.66 cM in B. napus genome. Totally, 24 putative QTLs were identified for plant height, the first branch height and branch number by using the complex interval mapping. The phenotypic variation was explained by individual QTL ranged from 5.00% to 15.26% for 11 QTLs of plant height, from 5.04% to 12.99% for seven QTLs of the first branch height, and from 5.95% to 8.14% for six QTLs of branch number. We collected 156 genes associated with plant height, 10 genes associated with the first branch height and 148 genes associated with branch number in Arabidopsis thaliana and searched the homology region of the QTL confidence interval E-value<1E–20 to screen the possible candidate genes. We found 20 genes associated with plant height, three genes associated with the first branch height and 12 genes associated with branch number. The plant height candidate genes ATGID1B/GID1B and WRI1 were found in QTL confidence interval on A07 and SLR/IAA14 and AXR2/IAA7 were found in QTL confidence interval on A08 in 2013 and 2014. The first branch height candidate gene PHT1;8 was found in QTLs q2013FBH-C05-1 and q2014FBH-C05-2 that had an overlapping confidence interval. Moreover, we found four genes associated with branch number that E-value from 0 to 3E–56 on A03 and C06, respectively.

      Fine Mapping and Map Integration of Brsc1 Gene in Dahuang Rape (Brassica rapa L.)
      LI Xin,XIAO Lu,DU De-Zhi
      Acta Agron Sin. 2015, 41(07):  1039-1046.  doi:10.3724/SP.J.1006.2015.01039
      Abstract ( 703 )   RICH HTML    PDF (939KB) ( 668 )   Save
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      Dahuang rape, a landrace originated from Qinghai Huangyuan, has bright yellow seed coat. Previous studies indicated that the yellow-seeded trait in Dahuang was controlled by a recessive gene (Brsc1), which was located in a 1.7 Mb interval on chromosome A9 of Brassica rapa (B. rapa). In order to better use the yellow-seeded resource, we further fine mapped the Brsc1 gene. BC4 and F2 populations, constructed from the cross of Dahuang and 09A-126 (brown-seeded, B. rapa), were used for fine mapping. New PCR markers were developed based on the information of the homologous region in B. rapa and the published SSR markers were used in polymorphism survey. A total of six markers (BrID10711, BrA5-BrA9) tightly linked to the target gene were obtained, wherein BrA5 co-segregated with Brsc1, and BrA9 was 0.69 cM away from the Brsc1 gene. So Brsc1 was further limited in a 1.2 Mb interval, approximately. The markers identified in this study were used to detect three types of individual plants in F2 population. BrA8 was identified as a co-dominant marker. Marker density of the region encompassing the Brsc1 gene was increased by integrating the markers from previous researches and this study. Sequence alignment with the genome of Arabidopsis thaliana was performed and a good homologous linear relationship between five markers and chromosome 1 of Arabidopsis thaliana was detected, which implied that homologous gene of the Brsc1 gene maybe located in the chromosome 1 of Arabidopsis thaliana. Markers obtained from this study would provide favorable conditions for map-based cloning of the Brsc1 and molecular marker-assisted selection (MAS) breeding of the yellow-seeded rape.

      Changes of DNA Methylation Levels and Patterns in Tea Plant (Camellia sinensis) during Cold Acclimation
      ZHOU Yan-Hua,CAO Hong-Li,YUE Chuan,WANG Lu,HAO Xin-Yuan,WANG Xin-Chao*,YANG Ya-Jun*
      Acta Agron Sin. 2015, 41(07):  1047-1055.  doi:10.3724/SP.J.1006.2015.01047
      Abstract ( 671 )   RICH HTML    PDF (1464KB) ( 862 )   Save
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      Low temperature is one of the most critical environmental factors that limit tea plant growth, survival and geographical distribution. Tea plant can enhance its cold tolerance after undergoing a period of cold acclimation. DNA methylation is one of the epigenetic phenomena, and can be altered by environmental stress in plant. In order to explore the relationship between DNA methylation and low temperature stress response in tea plant, methylation sensitive amplified polymorphism (MSAP) and high performance liquid chromatography (HPLC) were used to analyze the changes of DNA methylation level and pattern in this study. The MSAP results showed that 905, 968, and 970 methylated bands were amplified with 50 selected primers in non-acclimated sample (CK), fully acclimated and de-acclimated samples, with the methylation levels of 50.6%, 54.1%, and 54.2%, respectively. DNA methylation levels in fully acclimated and de-acclimated samples were increased compared with CK. HPLC results were similar with MSAP results. In addition, DNA demethylation and methylation were both occurred during cold acclimation, but the DNA methylation was increased more than the

      Screening of AhCaM-Interactive Proteins in Peanuts Using Yeast Two Hybrid System
      YANG Sha,LI Yan,GUO Feng,ZHANG Jia-Lei,MENG Jing-Jing,LI Meng,WAN Shu-Bo,LI Xin-Guo
      Acta Agron Sin. 2015, 41(07):  1056-1063.  doi:10.3724/SP.J.1006.2015.01056
      Abstract ( 687 )   RICH HTML    PDF (2724KB) ( 896 )   Save
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      Calmodulin is the most important known receptor of intracellular Ca2+, which is involved in regulation of many physiological activities. To further study the mechanism of CaM, we isolated and identified proteins that interact with AhCaM by yeast two-hybrid system. The pGBKT7-AhCaM bait vector without toxicity or auto-activation was firstly constructed with the peanut CaM gene. Then, the total RNA of peanut leaf was extracted and the mRNA was isolated, purified to be used as the templates to synthesize ds-cDNA by SMART technology. Ds-cDNA was amplified by long distance PCR. At last, the CaM interaction proteins were screened through co-transformation with bait vector and cDNA prey library. In the peanut cDNA library, five proteins interacting with AhCaM were identified. Among them, NAD kinase was a well-known protein to interact with CaM protein, and ubiquitin could interact with AhCaM, playing a role in development and stress resistance. The significant functional correlation between AhCaM and its interacting proteins peanut will help to elucidate the possible mechanisms of AhCaM in improving the tolerance of transgenic plants.

      Association Analysis between SSR Markers and Agronomic Traits in Barley
      SI Er-Jing,ZHANG Yu,WANG Jun-Cheng,MENG Ya-Xiong,LI Bao-Chun,MA Xiao-Le,SHANG Xun-Wu,WANG Hua-Jun
      Acta Agron Sin. 2015, 41(07):  1064-1072.  doi:10.3724/SP.J.1006.2015.01064
      Abstract ( 675 )   RICH HTML    PDF (672KB) ( 1239 )   Save
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      This study aimed at understanding the population structure of barley parent materials and identifying SSR markers associated with plant height, spike length, awn length, tiller number, effective tiller number, grain number per spike and thousand-grain weight. A total of 392 alleles were identified in 156 accessions using 86 polymorphic SSR markers with an average of 4.6 alleles per locus. The polymorphic information content ranged from 0.0612 to 0.8560. The 156 genotypes were divided into two populations according to structure analysis with SSR data. Eighteen markers were found to be associated with plant height, spike length, awn length, grain number per spike and thousand-grain weight using GLM (General Linear Model), and the phenotypic variation explained by a single marker ranged from 4.81% to 20.75%. Fourteen markers were found to be associated with plant height, spike length, awn length, effective tiller number, grain number per spike and thousand-grain weight using MLM(Mixed Linear Model), and the phenotypic variation explained by a single marker ranged from 6.64% to 31.55%. These associated markers provide a basis for future research.

      TILLAGE & CULTIVATION·PHYSIOLOGY & BIOCHEMISTRY
      Prediction of Leaf Area Index Using Hyperspectral Remote Sensing in Breeding Programs of Soybean
      QI Bo,ZHANG Ning,ZHAO Tuan-Jie,XING Guang-Nan,ZHAO Jing-Ming*,GAI Jun-Yi*
      Acta Agron Sin. 2015, 41(07):  1073-1085.  doi:10.3724/SP.J.1006.2015.01073
      Abstract ( 734 )   RICH HTML    PDF (2058KB) ( 1029 )   Save
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      Leaf area index (LAI) is an important parameter in observing field growth status and yield potential of crop plants, which is important in evaluating field growth performance of breeding lines in modern large scale plant breeding programs. The measurement of LAI and aboveground biomass (ABM) was synchronized with the information collection of the canopy hyperspectral reflectance at R2, R4, and R5 growth stages in a field experiment with 52 soybean varieties under randomized blocks design with three replications in two years. The results indicated that LAI have significant positive correlation with canopy spectral reflectance in the visible region (426–710 nm) and significant negative correlation in the near infrared region (748–1331 nm) (P<0.05). According to the linear correlation analysis between the vegetation indices and LAI in the literature, NDVI and RVI are superior vegetation indices for soybean LAI prediction. The linear and nonlinear regression models of LAI on NDVI and RVI vegetation indices were constructed and evaluated for all two–band combinations in the full spectral range of 350–2500 nm under 1 nm windows. Three single–stage regression models, i.e. R2 RVI (825, 586) model (y = 0.03x1.83), R4 RVI (763,606) model (y = 0.38e0.14x) and R5 RVI (744, 580) model (y = 0.06x1.79) were selected and validated as the best ones with fitness of 0.677, 0.639, 0.664 and less than 20% relative standard error, respectively, with their validation determination coefficients of 0.643, 0.612, 0.634, and around 20% validation standard error, respectively. Furthermore, the common core two–band combinations for both LAI and ABM prediction at R2, R4, and R5 were selected as 825 nm and 586 nm, 763 nm and 606 nm, and 744 nm and 580 nm, respectively. The obtained indices along with their prediction models can provide a technical support for quick and nondestructive field survey of soybean growth status in large scale breeding programs.

      Population Quality and Photosynthetic Characteristics after Anthesis in Yangmai 20 with Yield Potential of 9000 kg ha−1 in Rice–Wheat Rotation System
      DING Jin-Feng, HUANG Zheng-Jin, YUAN Yi, ZHU Xin-Kai, LI Chun-Yan, PENG Yong-Xin, GUO Wen-Shan
      Acta Agronomica Sinica. 2015, 41(07):  1086-1097.  doi:10.3724/SP.J.1006.2015.01086
      Abstract ( 637 )   RICH HTML    PDF (658KB) ( 930 )   Save
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      9000 kg ha-1) wheat production in rice–wheat rotation system. Wheat (Triticum aestivum L. cv. Yangmai 20) populations with yield level ≥9000 kg ha-1 (P1) and <9000 kg ha-2 leaf and 13.50–14.50 mg grain cm-2 leaf; LAI decrease rate of 0.13–0.15 d-1 after anthesis; population growth rate of 19–20 g m-2 d-1 after anthesis; photosynthetic potential of 1.03–1.18 million m2 d ha–1 after anthesis; and net assimilation of 9–11 g m–2 d–1 after anthesis. At the stages of 21 and 28 days after anthesis, the SPAD reading, net photosynthetic rate, malondialdehyde content, and activities of antioxidant enzymes (CAT, POD and SOD) in flag leaves were significantly correlated with grain yield. Our results suggest the following key points of cultivar potential for 9000 kg ha-1 yield potential of Yangmai 20 in rice–wheat rotation system are suitable population spike number as the basis; synchronous increases of grain number per spike and 1000-grain weight; high photosynthetic area and photosynthetic rate before anthesis; slow decrease of photosynthetic area after anthesis with its maintainable high level, and an abundant accumulated assimilate meeting to the sink enrichment.

      Relationship between Lignin Synthesis and Lodging Resistance at Seedlings Stage in Soybean Intercropping System
      ZOU Jun-Lin,LIU Wei-Guo,YUAN Jin,JIANG Tao,YE Su-Qin,DENG Yu-Chuan,YANG Chen-Yu,LUO Ling,YANG Wen-Yu
      Acta Agron Sin. 2015, 41(07):  1098-1104.  doi:10.3724/SP.J.1006.2015.01098
      Abstract ( 913 )   RICH HTML    PDF (374KB) ( 1136 )   Save
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      Stem physical characteristics are closely related to the crop lodging, increasing stem strength is available to resolve the problem of lodging.To explore the effect of intercropping soybean stem strength on the mechanism of shade tolerance and lodging resistance, we studied the relationship between lignin synthesis and lodging resistance. Three soybean cultivars with different shade tolerances were planted in maize–soybean intercropping and soybean monocropping, respectively. The lignin content, activities of phenylalanine ammonia-lyase (PAL), 4-coumarate:CoA ligase (4CL), cinnamyl alcohol dehydrogenase (CAD), peroxidase (POD) which involved in lignin synthesis in stem as well as the snapping resistance and lodging resistance index were determined at seedlings stage. The results showed that the intercropping soybean lodged seriously, the snapping resistance, lodging resistance index, lignin content and activities of the four enzymes were significantly lower than those of monocropping soybean at seedlings stage. The three soybean cultivars were affected differently by intercropping condition, the reduction of snapping resistance of Nandou 12 with strong shade tolerance was the least, its lodging resistance index, lignin content and activities of the four enzymes (PAL, 4CL, CAD, POD) also maintained a relatively high level. The lignin content of intercropping soybean seedling stem was significantly positively correlated with the snapping resistance (r = 0.890, P < 0.01) and the activities of 4CL, CAD, and significantly negatively correlated with the actual lodging percentage(r = –0.889, P < 0.01). In a word, the high activities of 4CL and CAD in the soybean stem provide a enzymatic basis to maintain higher lignin content, resulting in higher stem strength and higher lodging resistance in intercropping condition.

      Effects of Different Cultivation Patterns on Cotton Field Resources Use Efficiency in Yangtze River Valley
      ZHANG Chang-He,DAI Yan-Jiao,YANG Hong-Kun,ZHANG Xin-Yue,DU Xiang-Bei,CHEN Bing-Lin,ZHOU Zhi-Guo*
      Acta Agron Sin. 2015, 41(07):  1105-1111.  doi:10.3724/SP.J.1006.2015.01105
      Abstract ( 546 )   RICH HTML    PDF (276KB) ( 671 )   Save
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      The agricultural production in China is mainly dependent on nature environment. But the use efficiency of field resources in China is lower than those in developed countries, and the current crop cultivation theory and technology need to be innovated and improved continuously. The efficiency field stationary experiments using cotton cultivate Siza 3 with different cultivation patterns were carried out in high and low soil fertility levels in Dafeng, Jiangsu province. The cultivation patterns included super high cultivation patterns (SH), farmers practice cultivation (FP), high yield and high efficiency cultivation (HH). The result showed that lint yield of cotton was significantly affected by cultivation patterns and soil fertility levels. Lint yield difference was correlated with the differences of temperature production efficiency (TPE), radiation use efficiency (RUE) and nitrogen partial factor productivity (NPEP) under different cultivation patterns. Our results suggested that the key factor limited cotton production is the lower resources use efficiency. The lint yield, temperature and radiation use efficiency and nitrogen partial factor productivity of HH were 27.5%, 27.7%, 23.4%, and 10.1% higher than there of FP. Therefore, HH should be encouraged to extend in the Yangtze River Valley, and field resources use efficiency in wheat-cotton double cropping system should be further improved in the future for increasing cotton productivity.

      Response of Roots of Maize Varieties Released in Different Years to Low Nitrogen and Drought Stresses
      NIU Ping-Ping,MU Xin-Yuan,ZHANG Xing,YANG Chun-Shou,LI Chao-Hai
      Acta Agron Sin. 2015, 41(07):  1112-1120.  doi:10.3724/SP.J.1006.2015.01112
      Abstract ( 684 )   RICH HTML    PDF (458KB) ( 1021 )   Save
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      The changes in root characteristics were studied under low nitrogen stress (LN) and combined stress of low nitrogen and drought (LD) using six maize varieties released from 1973 to 2009, including Zhongdan 2, Danyu 13, Yedan 13, Nongda 108 Zhengdan 958, and a new variety Yudan 606. The result showed that root dry weight, root length and root surface area of the varieties increased at first and then decreased, finally increased again in the process of time. The increase of the three parameters in earlier released varieties could get more water and nutrition from soil, the decrease of these in later released varieties was available to reduce the redundant organ’s dry matter consumption, and the increase again of these in the new variety would meet water and nutrition requirements for yield increase continuously. Compared with the old varieties, root dry weight of the modern varieties changed smaller, root length and surface areas increased more, root average diameter became thinner, root bleeding sap decreased non-significantly under the LN and LD conditions. These results suggested that root characteristics of the varieties have been optimized gradually, the adjustment ability of root morphology, and the LN and LD stress tolerance in modern varieties have been increased.

      RESEARCH NOTES
      Genome-wide Association Analysis of Plant Height in Rapeseed (Brassica napus)
      TANG Min-Qiang,CHENG Xiao-Hui,TONG Chao-Bo,LIU Yue-Ying,ZHAO Chuan-Ji,DONG Cai-Hua,YU Jing-Yin,MA Xiao-Gen,HUANG Jun-Yan,LIU Sheng-Yi
      Acta Agron Sin. 2015, 41(07):  1121-1126.  doi:10.3724/SP.J.1006.2015.01121
      Abstract ( 1217 )   RICH HTML    PDF (1068KB) ( 1098 )   Save
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      Appropriate plant height is a trait related to lodging resistance and mechanical harvest, and ideal plant height is a basis of ideotype for high yield. The plant height of 371 rapeseed accessions collected from different growing regions in the world was measured in field experiments, all accessions were genotyped using a 60K SNP chip and 21856 informative SNPs were acquired, then the data of SNPs and plant height were used for genome-wide association analysis. Major results were as follows: 1) 4 significant SNPs related to plant height were detected, including Bn-A07-p3583161, Bn-scaff_22790_1-p1271170, Bn-scaff_20735_1-p42779, and Bn-scaff_18702_1-p589589, which located in A07, C01 and C02 chromosomes, and explained 11.33%, 11.75%, 12.31%, and 10.97% of phenotypic variation, respectively; 2) According to the reference genome annotation information, three candidate genes corresponding to the first three significant SNP were predicted, each gene was locates in 492.0, 9.5, and 69.5 kb away from the three SNP, respectively ; 3) The significant (two-tailed t-test) difference of plant height between means of two allelic groups of accessions corresponding to each significant SNP was 11.09, 15.12, 10.48, and 8.93 cm, respectively.

      Screening of Differentially Expressed Genes and Analysis of Plant Hormones Related Genes under Water Stress in Sugarcane
      LI Chang-Ning,XIE Jin-Lan,WANG Wei-Zan,LIANG Qiang,LI Yi-Jie,DONG Wen-Bin,LIU Xiao-Yan,YANG Li-Tao*,LI Yang-Rui*
      Acta Agron Sin. 2015, 41(07):  1127-1135.  doi:10.3724/SP.J.1006.2015.01127
      Abstract ( 775 )   RICH HTML    PDF (505KB) ( 1081 )   Save
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      Sugarcane is an increasingly economically and environmentally important C4 crop. Water stress limits enormously sugarcane productivity worldwide, and understanding the molecular mechanisms for sugarcane stress responses will be useful for sugarcane improvement by genetic manipulation. To investigate the transcriptome changes in response to water stress, we used microarrays to profile expressions of 15 593 genes in sugarcane exposed to drought. The results indicated that 300 and 853 differentially expressed genes were detected under moderate and severe water stresses, respectively. The expression of differentially expressed genes treated with moderate water stress was mainly up-regulated, however that treated with severe water stress was mainly down-regulated. To further characterize these genes, we used Gene Ontology (GO) for their annotation, the results showed that differentially expressed genes possessed the functions of binding, transporter, molecular transducer and catalytic activities and were involved in metabolic, biological regulation and cellular processes. Besides, hypothetical protein and no match annotated results were found to fill a large part of those genes, indicating that effective approach should be adopted to discover novel genes in sugarcane genomics. Water stress resulted in an increase in ABA and IAA contents but a depression in GA content. Classified by biological process, 46 plant hormone related genes were selected, further annotation analysis showed that the metabolic pathways of some plant hormone responsive genes were diverse or had crosstalk with each other, indicating the intersectionality and complexity of plant hormone signaling pathway. Additionally, the relative expressions of nine selected genes were validated by quantitative real time PCR (qRT-PCR), further confirming the reliability of microarray results.

      Regulative Effect of Optimized Cultivation Practice to the Root Vertical Distribution and Activity in Winter Wheat
      LI Hua-Wei,SI Ji-Sheng,XU Yue,LI Sheng-Dong,WU Jian-Jun,WANG Fa-Hong
      Acta Agron Sin. 2015, 41(07):  1136-1144.  doi:10.3724/SP.J.1006.2015.01136
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      To find out the cultivation practices, optimizing the construction of winter wheat root system, promoting root function, and enhancing the final grain yield, in the growing seasons of 2012–2013 and 2013–2014 we compared the root vertical distribution and activity in 090 cm soil layers, as well as grain yield and its components of winter wheat cultivar Luyuan502, with three treatments of cultivate techniques, viz., plow tillage-surface fertilization (PT-SF), rotary tillage-surface fertilization (RT-SF) and seedling belt rotary tillage-subsoiling-deep fertilization in different soil layers (SRT-SS-DF). Compared to PT-SF and RT-SF, SRT-SS-DF significantly increased thousand-kernel weight and spike number per hectare, resulting in 3.96–13.29% increase of grain yield. Root growth was stimulated in SRT-SS-DF treatment. For example, the root length density and dry weight density in 15–60 cm soil layer and total root surface area and active absorption area in 30–75 cm soil layer were significantly higher in SRT-SS-DF than in other treatments after jointing stage, especially in the fertilized soil layer (15–30 cm). At 20 days after anthesis (DAA), the total absorbing surface area and the active absorbing area of root in SRT-SS-DF were 66.3% and 56.5% higher than those in PT-SF and 75.9% and 59.8% higher than those in RT-SF, respectively. Besides, SRT-SS-DF alleviated the decline of root activity at late grain filling stage. From anthesis stage to 20 DAA, the reduction of root activity in 15–30 soil layer was 28.5% and 14.9% lower in SRT-SS-DF than in RT-SF and PT-SF, respectively. At 20 DAA, low root MDA content and high SOD activity in 1590 cm soil layer were observed in SRT-SS-DF. Especially, the SOD activity in 1530 cm soil layer in SRT-SS-DF was 20.6% and 10.9% higher than that in RP-SF and PR-SF, respectively. The root activity and the ratio of root dry weight (root dry weight in different soil layers/total root dry weight in 090 cm soil layer) in 1590 cm had a significant positive correlation with final grain yield. Our results suggest that optimizing integrated practices of seedling belt rotary tillage, seedling belt subsoiling and deep fertilization could be able to extend the root distribution in deep soil and increase the root activity, especially in fertilized soil layer, resulting in higher grain yield.

Co-sponsored:
the Crop Science Society of China
the Institute of Crop Science, CAAS
China Science Publishing & Media Ltd.
Published: Science Press
Editor-in-chief: Wan Jian-min
Associate Editors-in-Chief:
Chen Xiao-ya Yang Jian-chang Zhang Xian-long Wang Jian-kang Xu Ming-liang Liu Chun-ming Wang Dao-wen Sun Chuan-qing Ding Yan-feng Jin Wei-wei Chu Cheng-cai Cheng Wei-hong
Director of the editorial department:
Yan Chun-ling
CN 11-1809/S
ISSN 0496-3490
Post subscription code: 82-336

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  • Started in 2013
  • Covered by SCIE
  • Open access in ScienceDirect

Editor in chief: Wan Jian-min
CN 10-1112/S
ISSN 2095-5421, 2214-5141(online)
Online published:
https://www.sciencedirect.com/journal/the-crop-journal
Submission: https://www.editorialmanager.com/cj/
E-mail: cropjournal@caas.cn
Tel: 8610-82108548

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