栽培种花生遗传图谱的构建及主茎高和总分枝数QTL分析

栽培种花生是异源四倍体,基因组大,构建花生的分子遗传连锁图谱并对相关性状进行QTL定位研究的工作缓慢。本研究以遗传差异大的亲本组配杂交组合富川大花生×ICG6375构建F2作图群体,采用公开发表的2653对SSR引物,构建了一张含有234个SSR标记、分布于20个连锁群的栽培种花生遗传图谱。该图谱覆盖基因组的长度为1683.43c M,各个连锁群长度在36.11~131.48 c M之间,每个连锁群的标记数在6~15个之间,标记间的平均距离为7.19 c M。结合F3在湖北武汉和阳逻环境下的主茎高和总分枝数鉴定结果,应用Win QTLCart 2.5软件采用复合区间作图法进行了QTL定位和遗传效应分析。共检测到17个与主茎高和总分枝数相关的QTL位点,贡献率在0.10%~10.22%之间,分布于8个连锁群上。综合分析武汉和阳逻环境的鉴定结果,获得重复一致的与主茎高相关的6个QTL,其中q MHA061.1和q MHA062.1位于连锁群LG06上TC1A2~AHGS0153标记区间,贡献率为5.49%~8.95%;q MHA061.2和q MHA062.2位于LG06上AHGS1375~PM377标记区间,贡献率为2.93%~5.83%;q MHA092.2和q MHA091.1位于连锁群LG09上GM2839~EM87标记区间,贡献率为0.53%~9.43%。

Construction of Genetic Map and QTL Analysis for Mainstem Height and Total Branch Number in Peanut (Arachis hypogaea L.)

Peanut is an allotetraploid crop with a large genome. The construction of genetic linkage map and QTL mapping of related traits has little progress for peanut. In the present study, a genetic map consisting of 20 linkage groups was constructed with 234 SSR markers based on 2653 published SSR markers by using the F₂ population derived from the cross between Fuchuan Dahuasheng and ICG6375. The genetic map covers 1683.43 cM, and the length of each linkage group varies from 36.11 to 131.48 cM, the number of markers in each linkage group varies from 6 to 15, with an average distance of 7.19 cM. Combining with the data of main stem height and number of total branches of F₃ population in the environments of Wuhan and Yangluo, we performed QTL mapping and genetic effects analysis of QTLs by software WinQTLCart 2.5 using CIM (Composite Interval Mapping) method. As a result, 17 QTLs related to main stem height and number of total branches on eight linkage groups were detected with contribution percentage of 0.10%–10.22%. Comparing the QTLs detected in the environments of Wuhan and Yangluo, qMHA061.1 and qMHA062.1 were in the same linkage region of markers TC1A2–AHGS0153 of linkage group LG06 with contribution percentage of 5.49%–8.95%, qMHA061.2 and qMHA062.2 were between the markers AHGS1375 and PM377 on linkage group LG06 with contribution ratio of 2.93%–5.83%, qMHA092.2 and qMHA091.1 were in the same linkage region of the markers GM2839–EM87 in linkage group LG09 with contribution percentage of 0.53%–9.43%. The QTLs repeatedly detected are important for molecular breeding of peanut.