利用永久F_2群体定位小麦穗部性状相关的QTL

为发掘与小麦穗部性状相关的QTL,利用普通小麦BS366与白玉149杂交组合培育的73个DH群体为材料,构建了一套包含232个杂交组合的小麦永久F_2群体,基于90K SNP芯片标记构建了高密度遗传图谱,并利用该图谱对2个环境下的穗长、小穗数、穗粒数和千粒重进行QTL定位。结果发现,所构建的图谱总长19 533 cM,含有8 726个SNP标记,平均标记距离为2.24cM。结合群体基因分型结果,8 726个SNP标记合并为3 078个BIN标记,其中A基因组有1 283个(41.7%),B基因组有1 188个(38.6%),D基因组仅有607个(19.7%);共检测到96个QTL,分布在除3B和6B以外的19条染色体上,其中,控制穗长、小穗数、穗粒数和千粒重的QTL分别有20、59、6和11个,单一QTL可解释0.15%～12.34%的表型变异。51个QTL加性效应为正值,表明其加性效应来自于母本BS366;45个QTL加性效应为负值,表明其加性效应来自于父本白玉149。23个QTL的表型变异解释率大于5%,为主效QTL。

QTL Mapping for Spike Traits of Wheat Using Immortalized F2 Population

In order to explore the QTLs related to spike traits in wheat,a set of wheat immortalized F₂ population with 232 hybrid combinations was constructed based on 73 DH population derived from a cross between the common wheat BS366 and Baiyu 49.A high-density genetic map was constructed based on 90K SNP chip,and QTLs for spike length(SL),spikelet number(SN),kernel number(KN) and thousand-kernel weight(TKW)in two different environments were mapped.A total of 8 726 SNP were used to construct genetic map of 19 533 cM with the average distance of 2.24 cM between markers.8 726 SNP markers were combined to 3 078 BIN markers,1 283(41.7%) SNPs were found in A genome(41.7%),1 188(38.6%) in B genome,and only 607(19.7%) in D genome.96 QTLs were detected on 19 chromosomes except chromosomes 3B and 6B.Among them,20,59,6 and 11 QTLs for spike length,spikelet number,kernel number and thousand-kernal weight were identified,respectively.A single QTL explained 0.15%-12.34% of the phenotypic variation.The additive effect of 51 QTLs was positive,indicating that the additive effect was from the female parent BS366,and the additive effect of 45 QTLs was negative,indicating that the additive effect was from the male parent Baiyu 149.The probability of variation explained of 23 QTLs was more than 5%,and they were identified as the main QTLs.