中棉所70分离群体农艺性状相关QTL定位

摘要

[Objective] The aim of this study was to map quantitative trait loci (QTL) of yield-related traits in cotton.[Method] The F2 segregation population of upland cotton hybrid CCRI 70 was used.We used a total of 14 820 simple sequence repeats (SSR) primer pairs to screen the polymorphism between the parents (sGK156 and 901-001) of CCRI 70,and 267 polymorphic primer pairs were obtained.We used these polymorphic primers to identify the 250 individual plants of F2 population derived from CCRI 70,Joinmap 4.0 for linkage analysis,and composite interval mapping in WinQTLCart 2.5 to detect QTL of three traits (plant height,fruit branch number and boll number) in the 250 F2∶3 family lines.[Result] In the F2 population,we obtained 342 loci,and constructed a genetic linkage map covering 1 929.9 cM (accounting for 43.4％ of the cotton genome),with 312 SSR loci,35 linkage groups and an average interval of 9.2 cM between two neighbour markers.By QTL analysis on three traits of the 250 F2∶3 family lines,we identified 19 QTL,explaining 0.25％-11.28％ ofphenotypic variation,including 7 QTLs for plant height,4 for fruit branch number,and 8 for boll number,which locates on 8 chromosomes.[Conclusion] These results may help for breeding programs involved in marker-assisted development of new cultivars with improved yield.%[目的]定位棉花产量相关性状的数量性状基因座(Quantitative trait locus,QTL).[方法]以中棉所70的F2分离群体为遗传作图群体,利用从14 820对简单序列重复(Simple sequence repeat,SSR)引物中筛选出的267对两亲本间的多态性引物检测F2群体250个单株的标记基因型,利用Joinmap 4.0进行连锁分析,并通过WinQTLCart 2.5复合区间作图法对F2∶3群体的株高、单株结铃数和单株果枝数性状进行QTL定位.[结果]在F2群体中共获得342个SSR标记位点,并构建了包括312个标记、35个连锁群,总长1 929.9 cM的遗传连锁图谱(标记间平均距离为9.2 cM,覆盖棉花基因组的43.4％).经QTL定位,共检测到19个QTL,其中涉及株高的7个、单株果枝数4个、单株结铃数8个,这些QTL分布在8条染色体上,解释0.25％～11.28％的表型变异.[结论]这些与农艺性状相关的QTL有助于棉花产量分子标记辅助选择.