Increasing wheat yield is a long-term goal for wheat breeders around the world.Exploiting elite genetic resources and dissecting the genetic basis of important agronomic traits in wheat are the necessary methods for h...Increasing wheat yield is a long-term goal for wheat breeders around the world.Exploiting elite genetic resources and dissecting the genetic basis of important agronomic traits in wheat are the necessary methods for high-yield wheat breeding.This study evaluated nine crucial agronomic traits found in a natural population of 156 wheat varieties and77 landraces from Sichuan,China in seven environments over two years.The results of this investigation of agronomic traits showed that the landraces had more tillers and higher kernel numbers per spike (KNS),while the breeding varieties had higher thousand-kernel weight (TKW) and kernel weight per spike (KWS).The generalized heritability (H2) values of the nine agronomic traits varied from 0.74 to 0.95.Structure analysis suggested that the natural population could be divided into three groups using 43 198 single nucleotide polymorphism (SNP) markers from the wheat 55K SNP chip.A total of 67 quantitative trait loci (QTLs) were identified by the genome-wide association study (GWAS) analysis based on the Q+K method of a mixed linear model.Three important QTLs were analyzed in this study.Four haplotypes of QFTN.sicau-7BL.1 for fertile tillers number (FTN),three haplotypes of QKNS.sicau-1AL.2 for KNS,and four haplotypes of QTKW.sicau-3BS.1 for TKW were detected.FTN-Hap2,KNS-Hap1,and TKW-Hap2 were excellent haplotypes for each QTL based on the yield performance of 42 varieties in regional trials from 2002 to 2013.The varieties with all three haplotypes showed the highest yield compared to those with either two haplotypes or one haplotype.In addition,the KASP-AX-108866053 marker of QTL QKNS.sicau-1AL.2 was successfully distinguished between three haplotypes(or alleles) in 63 varieties based on the number of kernels per spike in regional trials between 2018 and 2021.These genetic loci and reliable makers can be applied in marker-assisted selection or map-based gene cloning for the genetic improvement of wheat yield.展开更多
植被生物量是全球碳循环的重要组成部分,是陆地生态系统与大气之间碳交换的重要环节,是定量研究全球气候变化与草地、荒漠生态系统之间的反馈调节作用等的基础。中国干旱半干旱区的草地、荒漠生态系统是重要的碳库类型,本文选取中国生...植被生物量是全球碳循环的重要组成部分,是陆地生态系统与大气之间碳交换的重要环节,是定量研究全球气候变化与草地、荒漠生态系统之间的反馈调节作用等的基础。中国干旱半干旱区的草地、荒漠生态系统是重要的碳库类型,本文选取中国生态系统研究网络(Chinese Ecosystem Research Network,CERN)中位于中国干旱半干旱区的2个草地生态系统观测研究站(海北站、内蒙古站)和5个荒漠生态系统类型观测研究站(鄂尔多斯站、阜康站、临泽站、奈曼站、沙坡头站)的典型生态系统,对其按照CERN生态系统长期观测规范开展长期观测获取的植被地上生物量的2005–2020年间生长季的月动态实测数据进行了收集整理与质量控制,并开展了样方原始调查数据到样地尺度观测数据的统计计算,生成了植被地上生物量数据集,可为中国干旱半干旱区草地和荒漠生态系统对全球气候变化响应及植被保育与可持续发展等研究提供地面观测数据支撑。展开更多
基金supported by the Sichuan Science and Technology Program , China ( 2022ZDZX0014 and 2021YFYZ0002)the Plan of Tianfu Qingcheng of Sichuan Province, China。
文摘Increasing wheat yield is a long-term goal for wheat breeders around the world.Exploiting elite genetic resources and dissecting the genetic basis of important agronomic traits in wheat are the necessary methods for high-yield wheat breeding.This study evaluated nine crucial agronomic traits found in a natural population of 156 wheat varieties and77 landraces from Sichuan,China in seven environments over two years.The results of this investigation of agronomic traits showed that the landraces had more tillers and higher kernel numbers per spike (KNS),while the breeding varieties had higher thousand-kernel weight (TKW) and kernel weight per spike (KWS).The generalized heritability (H2) values of the nine agronomic traits varied from 0.74 to 0.95.Structure analysis suggested that the natural population could be divided into three groups using 43 198 single nucleotide polymorphism (SNP) markers from the wheat 55K SNP chip.A total of 67 quantitative trait loci (QTLs) were identified by the genome-wide association study (GWAS) analysis based on the Q+K method of a mixed linear model.Three important QTLs were analyzed in this study.Four haplotypes of QFTN.sicau-7BL.1 for fertile tillers number (FTN),three haplotypes of QKNS.sicau-1AL.2 for KNS,and four haplotypes of QTKW.sicau-3BS.1 for TKW were detected.FTN-Hap2,KNS-Hap1,and TKW-Hap2 were excellent haplotypes for each QTL based on the yield performance of 42 varieties in regional trials from 2002 to 2013.The varieties with all three haplotypes showed the highest yield compared to those with either two haplotypes or one haplotype.In addition,the KASP-AX-108866053 marker of QTL QKNS.sicau-1AL.2 was successfully distinguished between three haplotypes(or alleles) in 63 varieties based on the number of kernels per spike in regional trials between 2018 and 2021.These genetic loci and reliable makers can be applied in marker-assisted selection or map-based gene cloning for the genetic improvement of wheat yield.
文摘植被生物量是全球碳循环的重要组成部分,是陆地生态系统与大气之间碳交换的重要环节,是定量研究全球气候变化与草地、荒漠生态系统之间的反馈调节作用等的基础。中国干旱半干旱区的草地、荒漠生态系统是重要的碳库类型,本文选取中国生态系统研究网络(Chinese Ecosystem Research Network,CERN)中位于中国干旱半干旱区的2个草地生态系统观测研究站(海北站、内蒙古站)和5个荒漠生态系统类型观测研究站(鄂尔多斯站、阜康站、临泽站、奈曼站、沙坡头站)的典型生态系统,对其按照CERN生态系统长期观测规范开展长期观测获取的植被地上生物量的2005–2020年间生长季的月动态实测数据进行了收集整理与质量控制,并开展了样方原始调查数据到样地尺度观测数据的统计计算,生成了植被地上生物量数据集,可为中国干旱半干旱区草地和荒漠生态系统对全球气候变化响应及植被保育与可持续发展等研究提供地面观测数据支撑。
文摘预制构件连接方法及其界面剪切性能影响整个输电铁塔装配式基础的受力和变形.针对螺栓连接易松动、变形大之类的问题,提出采用高强灌浆料灌注成形的十字形抗剪键作为输电铁塔装配式基础连接方案.采用室内剪切试验和数值模拟,研究该抗剪键连接的剪切性能,并与常用的螺栓连接进行对比分析.结果表明:十字形抗剪键剪切破坏模式为剪断型脆性破坏,破坏形态表现为以抗剪键为中心向外略有扩展成菱形.和螺栓连接相比,抗剪键连接的剪切强度略低,但剪切刚度显著提高.浇筑过程中灌浆料外溢对界面抗剪强度有提高作用.抗剪键的抗剪性能与灌浆料强度正相关,但提高灌浆料强度对抗剪性能提升并不明显.抗剪键深度对抗剪性能有影响,但在抗剪键深度超过20 mm后,抗剪键的抗剪性能不再提高.根据剪切试验和数值模拟结果,建议十字形抗剪键设计为长200 mm、宽20 mm、深20 mm.
