Deng Zhiying, Cui Yong, Han Qingdian, Fang Wenqi, Li Jifa, Tian Jichun
Group of Wheat Quality Breeding, State Key Laboratory of Crop Biology, Key Laboratory of Crop Biology of Shandong Province, Cooperation Innovation Centre of Efficient Production with High Annual Yield of Wheat and Corn, Agronomy College, Shandong Agricultural University, Tai'an, China.
Horticulture, College of Agriculture and Forestry Science, Linyi University, Linyi, China.
Front Plant Sci. 2017 Dec 15;8:2120. doi: 10.3389/fpls.2017.02120. eCollection 2017.
Spike-related traits such as spike length (Sl), fertile spikelet number (Fsn), sterile spikelet number (Ssn), grain number per spike (Gns), and thousand-kernel weight (Tkw) are important factors influencing wheat yield. However, reliably stable markers that can be used for molecular breeding in different environments have not yet been identified. In this study, a double haploid (DH) population was used for quantitative trait locus (QTL) mapping of five spike-related traits under four different nitrogen (N) supply dates in two locations and years. Seventy additive QTLs with phenotypic variation ranging from 4.12 to 34.74% and 10 major epistatic QTLs were identified. Eight important chromosomal regions on five chromosomes (1B, 2B, 2D, 5D, and 6A) were found. Sixteen stable QTLs were detected for which N application had little effect. Among those stable QTLs, , and , with phenotypic variation explained (PVE) of 10.4 and 24.2%, respectively, were flanked by markers and in the same order. The QTLs , and , with PVE ranging from 4.37 to 28.43%, collocated in the - marker interval. The consistent kernel wheat QTL () on the long arm of chromosome 6A, flanked by SSR markers and , showed PVE of 5.87-15.18%. Among these stable QTLs, the two flanking markers and have been validated using different varieties and populations for selecting Sl. Therefore, these results will be of great value for marker-assisted selection (MAS) in breeding programs and will accelerate the understanding of the genetic relationships among spike-related traits at the molecular level.
穗长（Sl）、可育小穗数（Fsn）、不育小穗数（Ssn）、每穗粒数（Gns）和千粒重（Tkw）等穗部相关性状是影响小麦产量的重要因素。然而，尚未鉴定出可在不同环境中用于分子育种的可靠稳定标记。本研究利用一个双单倍体（DH）群体，在两个地点和年份的四个不同施氮日期下，对五个穗部相关性状进行数量性状位点（QTL）定位。共鉴定出70个加性QTL，其表型变异范围为4.12%至34.74%，以及10个主要上位性QTL。在五条染色体（1B、2B、2D、5D和6A）上发现了八个重要的染色体区域。检测到16个稳定的QTL，施氮对其影响较小。在这些稳定的QTL中， 和 ，其表型变异解释率（PVE）分别为10.4%和24.2%，两侧标记顺序相同。QTL 、 和 ，PVE范围为4.37%至28.43%，位于 - 标记区间内。位于6A染色体长臂上的一致性籽粒小麦QTL（），两侧为SSR标记 和 ，PVE为5.87 - 15.18%。在这些稳定的QTL中，两个侧翼标记 和 已通过不同品种和群体进行验证，用于选择穗长。因此，这些结果对于育种计划中的标记辅助选择（MAS）具有重要价值，并将加速在分子水平上对穗部相关性状遗传关系的理解。
