海陆渐渗系棉花吐絮期叶绿素含量、荧光参数及相关性状的QTL定位分析

以海陆渐渗系13-1×辽棉12组配的195个单株的F2群体为作图群体,利用SSR(Simple sequence repeat)标记和Join Map3.0软件构建遗传连锁图谱,构建的遗传连锁图谱包含39个多态性标记、13个连锁群,该图谱总长1174.4 c M,覆盖棉花基因组的26.7%,利用Ici Mapping完备区间作图法对F2:3家系进行相关性状的QTL定位,共检测到30个叶绿素荧光参数、7个叶片干物质含量、6个叶面积指数、1个叶绿素含量的QTL位点,分布在8条染色体上,在同一染色体共标记区间内存在多个性状的QTL,部分位点加性遗传效应来自同一亲本,与干物质含量、最大光化学效应相关的QTL位点在3条染色体上不同标记区间内重复出现,与叶面积指数、最大光化学效应相关的QTL位点在4条染色体上不同标记区间内重复出现,表现出遗传上的一因多效或基因连锁效应,可用于高光效聚合育种。

QTL Mapping for Leaf Chlorophyll Content,Fast Chlorophyll Fluorescence Parameters and Related Traits in Cotton Introgression Lines during the Boll Opening Stage

In this study, a genetic linkage map was constructed for an F₂ population of 195 cotton plants derived from the cross between the parental introgression lines 13-1 and Liao 12 with SSR(simple sequence repeats) markers using the JoinMap 3.0 software. The map included 39 SSR loci and 13 linkage groups, covering 1174.4 cM and accounting for 26.7% of the cotton genome. Based on the inclusive composite interval mapping method with IciMapping, 44 QTLs(quantitative trait locus) were identified on eight chromosomes in the F_2:3 population, including 30 QTLs for chlorophyll fluorescence parameters, seven for leaf dry material content, six for leaf area index, and one for chlorophyll content. Multiple trait QTLs were located between the common range of markers on the same chromosome and the additive effect of some QTLs were inherited from the same parent. Some QTLs related to dry material content and maximal photochemical efficiency of PSⅡ appeared repeatedly in different ranges on three chromosomes and QTLs associated with leaf area index and maximal photochemical efficiency of PSⅡ recurred in different ranges on four chromosomes. These findings show that pleiotropism or genetic linkage could be used to combine many high-photosynthesis-efficiency genes into plants by genetic engineering.