Agronomy College, National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, Henan Agricultural University, 15 Longzihu College District, Zhengzhou, 450046, People's Republic of China.
Theor Appl Genet. 2018 Nov;131(11):2271-2285. doi: 10.1007/s00122-018-3181-8. Epub 2018 Sep 14.
Heading date is one of the most important traits in wheat breeding as it affects adaptation and yield potential. A genome-wide association study (GWAS) using the 90 K iSelect SNP genotyping assay indicated that a total of 306 loci were significantly associated with heading and flowering dates in 13 environments in Chinese common wheat from the Yellow and Huai wheat region. Of these, 105 loci were significantly correlated with both heading and flowering dates and were found in clusters on chromosomes 2, 5, 6, and 7. Based on differences in distribution of the vernalization and photoperiod genes among chromosomes, arms, or block regions, 13 novel, environmentally stable genetic loci were associated with heading and flowering dates, including RAC875_c41145_189 on 1DS, RAC875_c50422_299 on 2BL, and RAC875_c48703_148 on 2DS, that accounted for more than 20% phenotypic variance explained (PVE) of the heading/flowering date in at least four environments. GWAS and t test of a combination of SNPs and vernalization and photoperiod alleles indicated that the Vrn-B1, Vrn-D1, and Ppd-D1 genes significantly affect heading and flowering dates in Chinese common wheat. Based on the association of heading and flowering dates with the vernalization and photoperiod alleles at seven loci and three significant SNPs, optimal linear regression equations were established, which show that of the seven loci, the Ppd-D1 gene plays the most important role in modulating heading and flowering dates in Chinese wheat, followed by Vrn-B1 and Vrn-D1. Additionally, three novel genetic loci (RAC875_c41145_189, Excalibur_c60164_137, and RAC875_c50422_299) also show important effect on heading and flowering dates. Therefore, Ppd-D1, Vrn-B1, Vrn-D1, and the novel genetic loci should be further investigated in terms of improving heading and flowering dates in Chinese wheat. Further quantitative analysis of an F recombinant inbred lines population identified a major QTL that controls heading and flowering dates within the Ppd-D1 locus with PVEs of 28.4% and 34.0%, respectively; this QTL was also significantly associated with spike length, peduncle length, fertile spikelets number, cold resistance, and tiller number.
标题日期是小麦育种中最重要的特征之一，因为它会影响适应性和产量潜力。使用 90K iSelect SNP 基因分型测定对来自黄淮小麦区的中国普通小麦在 13 个环境中的 306 个位点与抽穗期和开花期进行全基因组关联研究（GWAS）表明，这些位点与抽穗期和开花期显著相关，其中 105 个位点与抽穗期和开花期显著相关，并在染色体 2、5、6 和 7 上聚类。基于春化和光周期基因在染色体、臂或块区之间的分布差异，与抽穗期和开花期相关的 13 个新的、环境稳定的遗传位点被鉴定出来，包括 1DS 上的 RAC875_c41145_189、2BL 上的 RAC875_c50422_299 和 2DS 上的 RAC875_c48703_148，这些位点在至少四个环境中解释了抽穗/开花日期的 20%以上的表型方差（PVE）。GWAS 和 SNPs 与春化和光周期等位基因的组合的 t 检验表明，Vrn-B1、Vrn-D1 和 Ppd-D1 基因显著影响中国普通小麦的抽穗期和开花期。基于七个位点和三个显著 SNPs 处的抽穗期和开花期与春化和光周期等位基因的关联，建立了最佳线性回归方程，表明在这七个位点中，Ppd-D1 基因在调节中国小麦的抽穗期和开花期方面起着最重要的作用，其次是 Vrn-B1 和 Vrn-D1。此外，三个新的遗传位点（RAC875_c41145_189、Excalibur_c60164_137 和 RAC875_c50422_299）也对抽穗期和开花期有重要影响。因此，应进一步研究 Ppd-D1、Vrn-B1、Vrn-D1 和新的遗传位点，以改善中国小麦的抽穗期和开花期。对一个 F2 重组自交系群体的进一步定量分析确定了一个主要的 QTL，该 QTL 位于 Ppd-D1 基因座内，控制抽穗期和开花期，具有 28.4%和 34.0%的 PVEs；该 QTL 还与穗长、穗颈长、可育小穗数、抗寒性和分蘖数显著相关。
