Key Laboratory of Plant Molecular Physiology, CAS Center for Excellence in Molecular Plant Sciences, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Planta. 2019 Dec;250(6):1967-1981. doi: 10.1007/s00425-019-03278-0. Epub 2019 Sep 16.
Totally, 48 loci responsible for six spike-related traits were identified in wheat, and a major locus QGl-4A for grain length was mapped and validated for marker-assisted selection in breeding. Wheat yield is determined by the number of spikes, number of grains per spike (GN), and one-thousand kernel weight (TKW), among which GN and TKW are greatly related to the spike development and thus the spike-related traits, including spike length (SL), number of spikelet per spike (SN), grain length (GL) and grain width (GW). To identify the key loci governing the spike-related traits (SL, SN, GN, TKW, GL and GW), we conducted the quantitative trait loci (QTL) analysis combined with wheat 660K SNP chip and Kompetitive allele-specific PCR (KASP) assay, using the F and F populations derived from Luohan6 (LH6) with big spike and grain and Zhengmai366 with small spike and grain, and identified a total of 48 QTLs on 18 chromosomes. Moreover, a major stable QTL for GL on chromosome 4A, designated as QGl-4A, was mapped into a 0.37 cM interval between KASP markers Xib4A-10 and Xib4A-12, corresponding to 20 Mb physical region in the Chinese Spring genome. This QTL explained 17.30% and 5.12% of the phenotypic variation for GL in the F and F populations. Further association analysis of flanking markers Xib4A-10 and Xib4A-12 in 192 wheat varieties showed that these two markers could be used for marker-assisted selection in breeding. These results provide valuable information for map-based cloning of the target genes involved in the regulation of spike-related traits in common wheat.
总共在小麦中鉴定出 48 个与 6 个穗相关性状相关的位点，并且定位和验证了一个控制粒长的主效位点 QGl-4A 用于育种中的标记辅助选择。小麦产量由穗数、每穗粒数（GN）和千粒重（TKW）决定，其中 GN 和 TKW 与穗发育密切相关，因此穗相关性状，包括穗长（SL）、每穗小穗数（SN）、粒长（GL）和粒宽（GW）。为了鉴定控制穗相关性状（SL、SN、GN、TKW、GL 和 GW）的关键基因座，我们进行了数量性状基因座（QTL）分析，结合了小麦 660K SNP 芯片和竞争性等位基因特异性 PCR（KASP）测定，利用大穗大粒的罗汉 6 号（LH6）和小穗小粒的郑麦 366 号衍生的 F 和 F 群体，共鉴定出 18 条染色体上的 48 个 QTL。此外，在 4A 染色体上定位到一个控制 GL 的主效稳定 QTL，命名为 QGl-4A，位于 KASP 标记 Xib4A-10 和 Xib4A-12 之间的 0.37 cM 区间，对应于中国春基因组中的 20 Mb 物理区域。该 QTL 解释了 F 和 F 群体中 GL 表型变异的 17.30%和 5.12%。在 192 个小麦品种中对侧翼标记 Xib4A-10 和 Xib4A-12 的关联分析表明，这两个标记可用于育种中的标记辅助选择。这些结果为普通小麦穗相关性状调控相关目标基因的图谱克隆提供了有价值的信息。
