Gao Fengmei, Wen Weie, Liu Jindong, Rasheed Awais, Yin Guihong, Xia Xianchun, Wu Xiaoxia, He Zhonghu
Key Laboratory of Soybean Biology, Soybean Research Institute, Ministry of Education, Northeast Agricultural UniversityHarbin, China; National Wheat Improvement Center, Institute of Crop Science, Chinese Academy of Agricultural SciencesBeijing, China; Keshan Sub-Academy, Heilongjiang Academy of Agricultural SciencesKeshan, China.
National Wheat Improvement Center, Institute of Crop Science, Chinese Academy of Agricultural Sciences Beijing, China.
Front Plant Sci. 2015 Dec 18;6:1099. doi: 10.3389/fpls.2015.01099. eCollection 2015.
Identification of genes for yield components, plant height (PH), and yield-related physiological traits and tightly linked molecular markers is of great importance in marker-assisted selection (MAS) in wheat breeding. In the present study, 246 F8 RILs derived from the cross of Zhou 8425B/Chinese Spring were genotyped using the high-density Illumina iSelect 90K single nucleotide polymorphism (SNP) assay. Field trials were conducted at Zhengzhou and Zhoukou of Henan Province, during the 2012-2013 and 2013-2014 cropping season under irrigated conditions, providing data for four environments. Analysis of variance (ANOVA) of agronomic and physiological traits revealed significant differences (P < 0.01) among RILs, environments, and RILs × environments interactions. Broad-sense heritabilities of all traits including thousand kernel weight (TKW), PH, spike length (SL), kernel number per spike (KNS), spike number/m(2) (SN), normalized difference in vegetation index at anthesis (NDVI-A) and at 10 days post-anthesis (NDVI-10), SPAD value of chlorophyll content at anthesis (Chl-A) and at 10 days post-anthesis (Chl-10) ranged between 0.65 and 0.94. A linkage map spanning 3609.4 cM was constructed using 5636 polymorphic SNP markers, with an average chromosome length of 171.9 cM and marker density of 0.64 cM/marker. A total of 866 SNP markers were newly mapped to the hexaploid wheat linkage map. Eighty-six QTL for yield components, PH, and yield-related physiological traits were detected on 18 chromosomes except 1D, 5D, and 6D, explaining 2.3-33.2% of the phenotypic variance. Ten stable QTL were identified across four environments, viz. QTKW.caas-6A.1, QTKW.caas-7AL, QKNS.caas-4AL, QSN.caas-1AL.1, QPH.caas-4BS.2, QPH.caas-4DS.1, QSL.caas-4AS, QSL.caas-4AL.1, QChl-A.caas-5AL, and QChl-10.caas-5BL. Meanwhile, 10 QTL-rich regions were found on chromosome 1BS, 2AL (2), 3AL, 4AL (2), 4BS, 4DS, 5BL, and 7AL exhibiting pleiotropic effects. These QTL or QTL clusters are tightly linked to SNP markers, with genetic distances to the closest SNPs ranging from 0 to 1.5 cM, and could serve as target regions for fine mapping, candidate gene discovery, and MAS in wheat breeding.
鉴定产量构成因素、株高（PH）以及与产量相关的生理性状的基因和紧密连锁的分子标记，在小麦育种的标记辅助选择（MAS）中具有重要意义。在本研究中，利用高密度Illumina iSelect 90K单核苷酸多态性（SNP）分析对周8425B/中国春杂交产生的246个F8重组自交系（RILs）进行基因分型。在2012 - 2013年和2013 - 2014年种植季，于河南省郑州和周口的灌溉条件下进行田间试验，提供了四个环境的数据。对农艺和生理性状的方差分析（ANOVA）显示，RILs、环境以及RILs×环境互作之间存在显著差异（P < 0.01）。包括千粒重（TKW）、PH、穗长（SL）、每穗粒数（KNS）、穗数/m²（SN）、开花期归一化植被指数（NDVI - A）和花后10天归一化植被指数（NDVI - 10）、开花期叶绿素含量SPAD值（Chl - A）和花后10天叶绿素含量SPAD值（Chl - 10）在内的所有性状的广义遗传力在0.65至0.94之间。利用5636个多态性SNP标记构建了一个跨度为3609.4 cM的连锁图谱，平均染色体长度为171.9 cM，标记密度为0.64 cM/标记。共有866个SNP标记新定位到六倍体小麦连锁图谱上。在除1D、5D和6D之外的18条染色体上检测到86个与产量构成因素、PH和与产量相关的生理性状相关的QTL，解释了2.3 - 33.2%的表型变异。在四个环境中鉴定出10个稳定的QTL，即QTKW.caas - 6A.1、QTKW.caas - 7AL、QKNS.caas - 4AL、QSN.caas - 1AL.1、QPH.caas - 4BS.2、QPH.caas - 4DS.1、QSL.caas - 4AS、QSL.caas - 4AL.1、QChl - A.caas - 5AL和QChl - 10.caas - 5BL。同时，在1BS、2AL（2个）、3AL、4AL（2个）、4BS、4DS、5BL和7AL染色体上发现了10个QTL富集区域，表现出多效性。这些QTL或QTL簇与SNP标记紧密连锁，与最接近的SNP的遗传距离在0至1.5 cM之间，可作为小麦育种中精细定位、候选基因发现和MAS的目标区域。
