以京农科728等18个黄淮海区主推夏播玉米品种为研究材料,设置6月10日(S1)、6月20日(S2)和6月30日(S3)共3个播期处理,研究夏播玉米品种在不同播期条件下的籽粒灌浆特性,以期为玉米品种选择及高产栽培提供参考和指导。结果表明:(1)成熟期...以京农科728等18个黄淮海区主推夏播玉米品种为研究材料,设置6月10日(S1)、6月20日(S2)和6月30日(S3)共3个播期处理,研究夏播玉米品种在不同播期条件下的籽粒灌浆特性,以期为玉米品种选择及高产栽培提供参考和指导。结果表明:(1)成熟期百粒重在不同播期及品种间存在极显著差异,不同播期间表现为S1(35.20 g)>S2(33.45 g)>S3(31.38 g);不同品种间变幅为28.50 g(华美1号)~36.37 g(京农科728)。(2)籽粒平均灌浆速率(Gave)在不同播期条件下表现为S1(0.74 g 100-grain^–1 d^–1)>S2(0.65 g 100-grain^–1 d^–1)>S3(0.57 g 100-grain^–1 d^–1),S1平均灌浆速率分别比S2、S3高0.09和0.17 g 100-grain^–1 d^–1,增幅分别为13.85%和29.82%;18个品种平均灌浆速率以京农科728(0.75 g 100-grain^–1 d^–1)最高,显著高于郑单958和先玉335(0.58 g 100-grain^–1 d^–1和0.67 g 100-grain^–1 d^–1),增幅为29.31%和11.94%。(3)不同播期间参试品种产量表现为S1(10,628.67 kg hm^–2)>S2(10,207.65 kg hm^–2)>S3(9144.59 kg hm^–2),S1分别较S2、S3高4.12%、16.23%;S1与S2下产量相差不大。不同品种间,NK815、MC121、京农科729、MC812、京农科728和先玉335产量相对较高,平均为10,730.56 kg hm^–2,显著高于郑单958(10,080.85 kg hm^–2),增幅为6.44%。(4)相关分析表明,产量与平均灌浆速率(0.70^**)、粒重(0.68^**)呈极显著正相关;与活跃灌浆期(-0.36^**)呈极显著负相关,而粒重与平均灌浆速率(0.58^**)呈极显著正相关。因此,黄淮海区夏播玉米抢时早播有利于获得更高产量,玉米品种可选择种植中熟或中早熟、灌浆速率高、活跃灌浆期适中、产量水平较高的京农科728、京农科729、MC812、MC121、NK815和先玉335等。在播种较晚或积温不足地区,可选择种植中早熟、灌浆速度快的高产型品种京农科728,6月30日播种、10月16日达生理成熟,可实现玉米高产。展开更多
纯度是玉米种子质量的重要指标之一,尤其杂交种自交株是影响田间产量的关键因素。KASP(kompetitive allele specific PCR)技术具有高通量、低成本的优点,适用于种子纯度检测。本研究基于12套杂交种及其父母本的三联体样本及335份玉米杂...纯度是玉米种子质量的重要指标之一,尤其杂交种自交株是影响田间产量的关键因素。KASP(kompetitive allele specific PCR)技术具有高通量、低成本的优点,适用于种子纯度检测。本研究基于12套杂交种及其父母本的三联体样本及335份玉米杂交种国家审定标准样品SNP指纹,从384个SNP基础位点筛选获得60个候选位点,位点转化为KASP引物的成功率为95%。综合考虑引物双亲互补率、多态性、稳定性和分型效果等多项指标,最终确定20个引物作为玉米杂交种纯度鉴定的核心引物,能够有效鉴定99.7%供试样品纯度。对于待测样品京科968通过SNP-DNA指纹数据库查询,并选择双亲互补型引物进行纯度鉴定。在检测的110个个体中,共检出1个自交苗和2个异型株,纯度为97.3%。同时,基于纯度核心引物对批量样品检测建立高通量纯度检测方案,具有快捷、准确、高通量和低成本的特点,为政府监管和企业提供了更多纯度鉴定方案的选择。展开更多
以京农科728等24个我国生产大面积推广的玉米品种为研究材料,比较不同类型玉米品种的冠层结构、光合及灌浆脱水特性差异,为适宜机收籽粒玉米品种选育和推广提供技术支撑。研究结果表明:(1)参试玉米品种平均机收产量、籽粒含水率、破碎...以京农科728等24个我国生产大面积推广的玉米品种为研究材料,比较不同类型玉米品种的冠层结构、光合及灌浆脱水特性差异,为适宜机收籽粒玉米品种选育和推广提供技术支撑。研究结果表明:(1)参试玉米品种平均机收产量、籽粒含水率、破碎率和杂质率分别为11,658.78 kg hm^(2)、24.66%、3.90%和0.83%。其中,以京2416为父本组配的京农科728等18个适宜机收籽粒玉米品种平均机收产量为11,802.70 kg hm^(2),显著高于郑单958和先玉335,分别增产7.69%和4.45%;收获时籽粒含水率均低于28%(平均为24.61%);破碎率低于5%(平均为3.42%),均达到国家机收籽粒标准。(2)以京2416为父本组配的京农科728等18个宜粒收玉米品种穗上茎叶夹角小,株型紧凑,冠层平均透光率高,冠层光分布更合理。(3)参试品种净光合速率和叶绿素含量平均为34.10μmol CO_(2)m^(-2)s^(-1)和8.91mg m^(2),其中以京2416为父本组配的18个品种净光合速率平均为35.21μmol CO_(2)m^(-2)s^(-1),较郑单958和先玉335高19.60%和6.73%;叶绿素含量平均为9.87 mg m^(2),较郑单958和先玉335高61.54%和68.43%。(4)以京2416为父本组配的18个品种灌浆速率和生理成熟后脱水速率分别平均为0.83 g 100-grain;d^(-1)和0.55%d^(-1),均显著高于郑单958和先玉335,表现为较低的收获时籽粒含水率。(5)相关分析表明,参试玉米品种产量与净光合速率、灌浆速率呈极显著正相关;净光合速率与茎叶夹角呈极显著负相关,与透光率、叶绿素含量呈极显著正相关;收获时籽粒含水率与破碎率、杂质率和生理成熟时籽粒含水率呈极显著正相关,与生理成熟后脱水速率呈极显著负相关,与灌浆速率呈显著负相关。由此可见,以京2416为父本组配的京农科728等18个玉米品种株型紧凑、冠层透光率高、光合能力强、籽粒灌浆和脱水速率高,可实现较低的籽粒含水率和较高的机收籽粒质量。展开更多
The germplasm resources for the S-type male sterility is rich in maize and it is resistant to Bipolaris maydis race T and CI, but the commercial application of S-type cytoplasmic male sterility （CMS-S） in maize hybr...The germplasm resources for the S-type male sterility is rich in maize and it is resistant to Bipolaris maydis race T and CI, but the commercial application of S-type cytoplasmic male sterility （CMS-S） in maize hybrid industry is greatly compromised because of its common fertility instability. Currently, the existence of multiple minor effect loci in specific nuclear genetic backgrounds was considered as the molecular mechanism for this phenomenon. In the present study, we evaluated the fertility segregation of the different populations with the fertility instable material FIL-H in two environments of Beijing and Hainan, China. Our results indicated that the fertility instability of FIL-H was regulated by multiple genes, and the expression of these genes was sensitive to environmental factors. Using RNA sequencing （RNA-seq） technology, transcriptomes of the sterile plants and partially fertile plants resulted from the backcross of FIL-HxJing 724 in Hainan were analyzed and 2 108 genes with different expression were identified, including 1 951 up-regulated and 157 down-regulated genes. The cluster analysis indicated that these differentially expressed genes （DEGs） might play roles in many biological processes, such as the energy production and conversion, carbohydrate metabolism and signal transduction. In addition, the path- way of the starch and sucrose metabolism was emphatically investigated to reveal the DEGs during the process of starch biosynthesis between sterile and partially fertile plants, which were related to the key catalytic enzymes, such as ADP-G pyrophosphorylase, starch synthase and starch branching enzyme. The up-regulation of these genes in the partially fertile plant may promote the starch accumulation in its pollen. Our data provide the important theoretical basis for the further exploration of the molecular mechanism for the fertility instability in CMS-S maize.展开更多
In this study, a forward cDNA library was constructed by suppression subtractive hybridization using seedling leaves of CN165, a drought-tolerant maize inbred line. In the suppression subtractive hybridization （SSH）...In this study, a forward cDNA library was constructed by suppression subtractive hybridization using seedling leaves of CN165, a drought-tolerant maize inbred line. In the suppression subtractive hybridization （SSH） library, 672 positive clones were picked up randomly. After polymerase chain reaction （PCR） of each clone, all the single clones were sequenced. Totally 598 available sequences were obtained. After cluster analysis of the EST sequences, 80 uniESTs were obtained, among which 57 uniESTs were contigs and 23 uniESTs were singlets. The results of BLASTN showed that all the uniESTs had homologous sequences in the nr database. The BLASTX results indicated that 68 uniESTs had significant protein homology, 8 uniESTs with homology of unknown proteins and putative proteins, and 4 uniESTs without protein homology. Those drought stress-induced genes were involved in many metabolism pathways to regulate plant growth and development under drought stress.展开更多
Maize landraces White Dent and Golden Queen played a very important role in the pre-hybrid era of maize production in China. However, dozens of accessions with the same names of White Dent and Golden Queen are preserv...Maize landraces White Dent and Golden Queen played a very important role in the pre-hybrid era of maize production in China. However, dozens of accessions with the same names of White Dent and Golden Queen are preserved in China National Genebank （CNG）. The present study investigated the genetic diversity of these two important groups of maize landraces, as well as the relationships within and among them. Thirty-four landrace accessions with the name of White Dent and 10 with Golden Queen preserved in CNG were fingerprinted with 52 simple sequence repeats with tailed primer M13. Summary statistics including average number of alleles per locus, gene diversity/expected heterozygosity, and observed heterozygosity were carried out using PowerMarker ver. 3.25 software. The test of Hardy-Weinberg equilibrium （HWE） and linkage disequilibrium （LD） of all the 44 maize landrace accessions were also performed by PowerMarker. We observed a significant differentiation in terms of the average number of alleles between White Dent and Golden Queen （6.44 alleles per locus in White Dent, 4.48 in Golden Queen）, while both groups of maize landraces had a relatively high but similar gene diversity （0.61 of White Dent, 0.63 of Golden Queen）. The fixation index （FST） was only 0.0044, while the percentage of loci deviated from Hardy-Weinberg equilibrium within these two groups of White Dent and Golden Queen was 32.69 and 3.92%, respectively. The rather high genetic diversity and average number of alleles per locus confirmed that both groups of landraces had a rather broad germplasm base. The extremely low fixation index showed that there was little genetic variation between White Dent and Golden Queen and the molecular variation within these two groups was remarkably high, indicating no genetic drift between White Dent and Golden Queen and suggesting different improvement approaches to these two important groups of landraces. Hardy-Weinberg equilibrium test revealed that the group of White Dent was deviated from HWE, whereas Golden Queen was under HWE.展开更多
Understanding genetic diversity and population structure of landraces is important in utilization of these germplasm in breeding programs. In the present study, a total of 143 core maize landraces from the South Maize...Understanding genetic diversity and population structure of landraces is important in utilization of these germplasm in breeding programs. In the present study, a total of 143 core maize landraces from the South Maize Region （SR） of China, which can represent the general profile of the genetic diversity in the landraces germplasm of SR, were genotyped by 54 DNA microsatellite markers. Totally, 517 alleles （ranging from 4 to 22） were detected among these landraces, with an average of 9.57 alleles per locus. The total gene diversity of these core landraces was 0.61, suggesting a rather higher level of genetic diversity. Analysis of population structure based on Bayesian method obtained the samilar result as the phylogeny neighbor-joining （N J） method. The results indicated that the whole set of 143 core landraces could be clustered into two distinct groups. All landraces from Guangdong, Hainan, and 15 landraces from Jiangxi were clustered into group 1, while those from the other regions of SR formed the group 2. The results from the analysis of genetic diversity showed that both of groups possessed a similar gene diversity, but group 1 possessed relatively lower mean alleles per locus （6.63） and distinct alleles （91） than group 2 （7.94 and 110, respectively）. The relatively high richness of total alleles and distinct alleles preserved in the core landraces from SR suggested that all these germplasm could be useful resources in germplasm enhancement and maize breeding in China.展开更多
Toxic symptoms and tolerance mechanisms of heavy metal in maize are well documented. However, limited information is available regarding the changes in the proteome of maize seedling roots in response to cadmium(Cd) s...Toxic symptoms and tolerance mechanisms of heavy metal in maize are well documented. However, limited information is available regarding the changes in the proteome of maize seedling roots in response to cadmium(Cd) stress. Here, we employed an i TRAQ-based quantitative proteomic approach to characterize the dynamic alterations in the root proteome during early developmental in maize seedling. We conducted our proteomic experiments in three-day seedling subjected to Cd stress, using roots in four time points. We identified a total of 733, 307, 499, and 576 differentially abundant proteins after 12, 24, 48, or 72 h of treatment, respectively. These proteins displayed different functions, such as ribosomal synthesis, reactive oxygen species homeostasis, cell wall organization, cellular metabolism, and carbohydrate and energy metabolism. Of the 166 and 177 proteins with higher and lower abundance identified in at least two time points, 14 were common for three time points. We selected nine proteins to verify their expression using quantitative real-time PCR. Proteins involved in the ribosome pathway were especially responsive to Cd stress. Functional characterization of the proteins and the pathways identified in this study could help our understanding of the complicated molecular mechanism involved in Cd stress responses and create a list of candidate gene responsible for Cd tolerance in maize seeding roots.展开更多
文摘以京农科728等18个黄淮海区主推夏播玉米品种为研究材料,设置6月10日(S1)、6月20日(S2)和6月30日(S3)共3个播期处理,研究夏播玉米品种在不同播期条件下的籽粒灌浆特性,以期为玉米品种选择及高产栽培提供参考和指导。结果表明:(1)成熟期百粒重在不同播期及品种间存在极显著差异,不同播期间表现为S1(35.20 g)>S2(33.45 g)>S3(31.38 g);不同品种间变幅为28.50 g(华美1号)~36.37 g(京农科728)。(2)籽粒平均灌浆速率(Gave)在不同播期条件下表现为S1(0.74 g 100-grain^–1 d^–1)>S2(0.65 g 100-grain^–1 d^–1)>S3(0.57 g 100-grain^–1 d^–1),S1平均灌浆速率分别比S2、S3高0.09和0.17 g 100-grain^–1 d^–1,增幅分别为13.85%和29.82%;18个品种平均灌浆速率以京农科728(0.75 g 100-grain^–1 d^–1)最高,显著高于郑单958和先玉335(0.58 g 100-grain^–1 d^–1和0.67 g 100-grain^–1 d^–1),增幅为29.31%和11.94%。(3)不同播期间参试品种产量表现为S1(10,628.67 kg hm^–2)>S2(10,207.65 kg hm^–2)>S3(9144.59 kg hm^–2),S1分别较S2、S3高4.12%、16.23%;S1与S2下产量相差不大。不同品种间,NK815、MC121、京农科729、MC812、京农科728和先玉335产量相对较高,平均为10,730.56 kg hm^–2,显著高于郑单958(10,080.85 kg hm^–2),增幅为6.44%。(4)相关分析表明,产量与平均灌浆速率(0.70^**)、粒重(0.68^**)呈极显著正相关;与活跃灌浆期(-0.36^**)呈极显著负相关,而粒重与平均灌浆速率(0.58^**)呈极显著正相关。因此,黄淮海区夏播玉米抢时早播有利于获得更高产量,玉米品种可选择种植中熟或中早熟、灌浆速率高、活跃灌浆期适中、产量水平较高的京农科728、京农科729、MC812、MC121、NK815和先玉335等。在播种较晚或积温不足地区,可选择种植中早熟、灌浆速度快的高产型品种京农科728,6月30日播种、10月16日达生理成熟,可实现玉米高产。
文摘纯度是玉米种子质量的重要指标之一,尤其杂交种自交株是影响田间产量的关键因素。KASP(kompetitive allele specific PCR)技术具有高通量、低成本的优点,适用于种子纯度检测。本研究基于12套杂交种及其父母本的三联体样本及335份玉米杂交种国家审定标准样品SNP指纹,从384个SNP基础位点筛选获得60个候选位点,位点转化为KASP引物的成功率为95%。综合考虑引物双亲互补率、多态性、稳定性和分型效果等多项指标,最终确定20个引物作为玉米杂交种纯度鉴定的核心引物,能够有效鉴定99.7%供试样品纯度。对于待测样品京科968通过SNP-DNA指纹数据库查询,并选择双亲互补型引物进行纯度鉴定。在检测的110个个体中,共检出1个自交苗和2个异型株,纯度为97.3%。同时,基于纯度核心引物对批量样品检测建立高通量纯度检测方案,具有快捷、准确、高通量和低成本的特点,为政府监管和企业提供了更多纯度鉴定方案的选择。
文摘以京农科728等24个我国生产大面积推广的玉米品种为研究材料,比较不同类型玉米品种的冠层结构、光合及灌浆脱水特性差异,为适宜机收籽粒玉米品种选育和推广提供技术支撑。研究结果表明:(1)参试玉米品种平均机收产量、籽粒含水率、破碎率和杂质率分别为11,658.78 kg hm^(2)、24.66%、3.90%和0.83%。其中,以京2416为父本组配的京农科728等18个适宜机收籽粒玉米品种平均机收产量为11,802.70 kg hm^(2),显著高于郑单958和先玉335,分别增产7.69%和4.45%;收获时籽粒含水率均低于28%(平均为24.61%);破碎率低于5%(平均为3.42%),均达到国家机收籽粒标准。(2)以京2416为父本组配的京农科728等18个宜粒收玉米品种穗上茎叶夹角小,株型紧凑,冠层平均透光率高,冠层光分布更合理。(3)参试品种净光合速率和叶绿素含量平均为34.10μmol CO_(2)m^(-2)s^(-1)和8.91mg m^(2),其中以京2416为父本组配的18个品种净光合速率平均为35.21μmol CO_(2)m^(-2)s^(-1),较郑单958和先玉335高19.60%和6.73%;叶绿素含量平均为9.87 mg m^(2),较郑单958和先玉335高61.54%和68.43%。(4)以京2416为父本组配的18个品种灌浆速率和生理成熟后脱水速率分别平均为0.83 g 100-grain;d^(-1)和0.55%d^(-1),均显著高于郑单958和先玉335,表现为较低的收获时籽粒含水率。(5)相关分析表明,参试玉米品种产量与净光合速率、灌浆速率呈极显著正相关;净光合速率与茎叶夹角呈极显著负相关,与透光率、叶绿素含量呈极显著正相关;收获时籽粒含水率与破碎率、杂质率和生理成熟时籽粒含水率呈极显著正相关,与生理成熟后脱水速率呈极显著负相关,与灌浆速率呈显著负相关。由此可见,以京2416为父本组配的京农科728等18个玉米品种株型紧凑、冠层透光率高、光合能力强、籽粒灌浆和脱水速率高,可实现较低的籽粒含水率和较高的机收籽粒质量。
基金supported by the National Key Technologies R&D Program of China during the 12th Five-year Plan period(2014BAD01B09)the Beijing Postdoctoral Research Foundation,China(2014ZZ-68)+2 种基金the Sci-Technology Innovation Project of Beijing Academy of Agriculture and Forestry Science(BAAFS),China(KJCX20140202)the Innovative Team Construction Project of BAAFS,China(JNKYT201603)the Postdoctoral Scientific Fund of BAAFS,China(2014013)
文摘The germplasm resources for the S-type male sterility is rich in maize and it is resistant to Bipolaris maydis race T and CI, but the commercial application of S-type cytoplasmic male sterility （CMS-S） in maize hybrid industry is greatly compromised because of its common fertility instability. Currently, the existence of multiple minor effect loci in specific nuclear genetic backgrounds was considered as the molecular mechanism for this phenomenon. In the present study, we evaluated the fertility segregation of the different populations with the fertility instable material FIL-H in two environments of Beijing and Hainan, China. Our results indicated that the fertility instability of FIL-H was regulated by multiple genes, and the expression of these genes was sensitive to environmental factors. Using RNA sequencing （RNA-seq） technology, transcriptomes of the sterile plants and partially fertile plants resulted from the backcross of FIL-HxJing 724 in Hainan were analyzed and 2 108 genes with different expression were identified, including 1 951 up-regulated and 157 down-regulated genes. The cluster analysis indicated that these differentially expressed genes （DEGs） might play roles in many biological processes, such as the energy production and conversion, carbohydrate metabolism and signal transduction. In addition, the path- way of the starch and sucrose metabolism was emphatically investigated to reveal the DEGs during the process of starch biosynthesis between sterile and partially fertile plants, which were related to the key catalytic enzymes, such as ADP-G pyrophosphorylase, starch synthase and starch branching enzyme. The up-regulation of these genes in the partially fertile plant may promote the starch accumulation in its pollen. Our data provide the important theoretical basis for the further exploration of the molecular mechanism for the fertility instability in CMS-S maize.
文摘In this study, a forward cDNA library was constructed by suppression subtractive hybridization using seedling leaves of CN165, a drought-tolerant maize inbred line. In the suppression subtractive hybridization （SSH） library, 672 positive clones were picked up randomly. After polymerase chain reaction （PCR） of each clone, all the single clones were sequenced. Totally 598 available sequences were obtained. After cluster analysis of the EST sequences, 80 uniESTs were obtained, among which 57 uniESTs were contigs and 23 uniESTs were singlets. The results of BLASTN showed that all the uniESTs had homologous sequences in the nr database. The BLASTX results indicated that 68 uniESTs had significant protein homology, 8 uniESTs with homology of unknown proteins and putative proteins, and 4 uniESTs without protein homology. Those drought stress-induced genes were involved in many metabolism pathways to regulate plant growth and development under drought stress.
基金supported by the Special Program for Crop Germplasm Resources of the Ministry of Agriculture [(NB07-2130135-(25-30)-05]Natural Science Foundation of Beijing (6071003)+1 种基金Innovation Platform Program for Basic Research of Agricultural Breeding in Beijing (YZPT02-06)Scientific and Technological Key Project in Chongqing for Elite Variety Innovation of Rice and Maize (CSTC 2007AB1045)
文摘Maize landraces White Dent and Golden Queen played a very important role in the pre-hybrid era of maize production in China. However, dozens of accessions with the same names of White Dent and Golden Queen are preserved in China National Genebank （CNG）. The present study investigated the genetic diversity of these two important groups of maize landraces, as well as the relationships within and among them. Thirty-four landrace accessions with the name of White Dent and 10 with Golden Queen preserved in CNG were fingerprinted with 52 simple sequence repeats with tailed primer M13. Summary statistics including average number of alleles per locus, gene diversity/expected heterozygosity, and observed heterozygosity were carried out using PowerMarker ver. 3.25 software. The test of Hardy-Weinberg equilibrium （HWE） and linkage disequilibrium （LD） of all the 44 maize landrace accessions were also performed by PowerMarker. We observed a significant differentiation in terms of the average number of alleles between White Dent and Golden Queen （6.44 alleles per locus in White Dent, 4.48 in Golden Queen）, while both groups of maize landraces had a relatively high but similar gene diversity （0.61 of White Dent, 0.63 of Golden Queen）. The fixation index （FST） was only 0.0044, while the percentage of loci deviated from Hardy-Weinberg equilibrium within these two groups of White Dent and Golden Queen was 32.69 and 3.92%, respectively. The rather high genetic diversity and average number of alleles per locus confirmed that both groups of landraces had a rather broad germplasm base. The extremely low fixation index showed that there was little genetic variation between White Dent and Golden Queen and the molecular variation within these two groups was remarkably high, indicating no genetic drift between White Dent and Golden Queen and suggesting different improvement approaches to these two important groups of landraces. Hardy-Weinberg equilibrium test revealed that the group of White Dent was deviated from HWE, whereas Golden Queen was under HWE.
基金supported by the Program for Germplasm Innovation and Utilization from the Minis-try of Agrculture of China (2006BAD13B03)Beijing Natural Science Foundation (6071003)Doctoral Foundation of Southwest University, China(SWUB2008037)
文摘Understanding genetic diversity and population structure of landraces is important in utilization of these germplasm in breeding programs. In the present study, a total of 143 core maize landraces from the South Maize Region （SR） of China, which can represent the general profile of the genetic diversity in the landraces germplasm of SR, were genotyped by 54 DNA microsatellite markers. Totally, 517 alleles （ranging from 4 to 22） were detected among these landraces, with an average of 9.57 alleles per locus. The total gene diversity of these core landraces was 0.61, suggesting a rather higher level of genetic diversity. Analysis of population structure based on Bayesian method obtained the samilar result as the phylogeny neighbor-joining （N J） method. The results indicated that the whole set of 143 core landraces could be clustered into two distinct groups. All landraces from Guangdong, Hainan, and 15 landraces from Jiangxi were clustered into group 1, while those from the other regions of SR formed the group 2. The results from the analysis of genetic diversity showed that both of groups possessed a similar gene diversity, but group 1 possessed relatively lower mean alleles per locus （6.63） and distinct alleles （91） than group 2 （7.94 and 110, respectively）. The relatively high richness of total alleles and distinct alleles preserved in the core landraces from SR suggested that all these germplasm could be useful resources in germplasm enhancement and maize breeding in China.
基金supported by the Foundation for Young Scientist of Beijing Academy of Agriculture & Forestry Sciences, China (QNJJ201505)the National Key Research and Development Program of China (SQ2016ZY03002163)
文摘Toxic symptoms and tolerance mechanisms of heavy metal in maize are well documented. However, limited information is available regarding the changes in the proteome of maize seedling roots in response to cadmium(Cd) stress. Here, we employed an i TRAQ-based quantitative proteomic approach to characterize the dynamic alterations in the root proteome during early developmental in maize seedling. We conducted our proteomic experiments in three-day seedling subjected to Cd stress, using roots in four time points. We identified a total of 733, 307, 499, and 576 differentially abundant proteins after 12, 24, 48, or 72 h of treatment, respectively. These proteins displayed different functions, such as ribosomal synthesis, reactive oxygen species homeostasis, cell wall organization, cellular metabolism, and carbohydrate and energy metabolism. Of the 166 and 177 proteins with higher and lower abundance identified in at least two time points, 14 were common for three time points. We selected nine proteins to verify their expression using quantitative real-time PCR. Proteins involved in the ribosome pathway were especially responsive to Cd stress. Functional characterization of the proteins and the pathways identified in this study could help our understanding of the complicated molecular mechanism involved in Cd stress responses and create a list of candidate gene responsible for Cd tolerance in maize seeding roots.
