木薯分子标记遗传连锁图谱的构建及相关性状QTL定位

用木薯推广品种KU50为母本,SC124为父本通过杂交得到包含235个单株的F1分离群体,构建了一张包含150个标记的分子遗传连锁图谱,其中EST-SSR有72个位点,SSR有58个位点,SRAP有20个位点,这些位点分布了21个连锁群,总长度为1434.48cM,标记间距为9.56cM.遗传图谱的连锁群的长度在16.89～139.63 cM,标记的间距是0.2～47.0cM,标记位点比较多的是LG1、LG2、LG4、LG9、LG10,分别是17、18、13、14、15个,而标记数最少的是LG20,只有2个标记.用IciQTLMaping3.2软件在LOD=2.5进行QTL分析,检测了块根产量(WCY)、耐寒性分析(CR11、CR12)、干物质含量(DMC11、DMC12)3个木薯数量性状,总共得到34个QTL位点,分布在12个连锁群上.其中关于WCY的QTL位点总共有17个,贡献率为21.70％～55.23％,平均贡献率为40.74％;CR11相关的QTL位点有4个,贡献率为2.97％～33.29％,平均贡献率为18.20％.与CR12相关的QTL定位有3个,贡献率为5.23％～29.85％,平均贡献率为18.28％；与DMC12性状相关的QTL位点有4个,贡献率为15.87％～38.52％,平均贡献率为26.24％；与DMC11性状相关的位点有6个,贡献率为13.84％～22.15％,平均贡献率为17.56％.

Construction of the Molecular Genetic Linkage Map and QTL Analysis for Related Traits in Cassava(Manihot esculenta Crantz)

The genetic linkage map of cassava with a total of 150 molecular markers, 72 EST-SSR markers, 58 simple sequence repeat(SSR)markers, 20 sequence-related amplified polymorphism(SRAP)markers was constructed on the experimental population with 235 lines from F1 hybrid between parents SC124 and KU50. The genetic map was consisted of 21 linkage group and spanned a 1 434.48 cM, with the average marker interval being 9.56 cM. The markers were distributed evenly. The markers for LG1, LG2, LG4, LG9 and LG10 was 17, 18, 13, 14, 15, respectively, while that for LG20 was only 2. The linkage group length varied from 16.89 cM(LG20)to 139.63 cM(LG1)with intervals between markers ranging from 0.2 cM to 47.0 cM. The IciQTLMapping 3.2 software under LOD=2.5 was used to detect QTL for leaf abscission(LA), cold resistance in 2011 and 2012(CR11, CR12), root dry matter content in 2011 and 2012(DMC11, DMC12). A total of 34 QTLs in 12 linkage groups were found for three trials. For WCY, 17 QTLs with the PVE ranging from 28.64% to 40.40%, or an average 39.89%, were detected, while for DMC11, only six QTLs with the PVE ranging form 13.84% to 22.15%, or an average 17.56% were detected. The QTLs for CR11, CR12, DMC11, DMC12 were 4 with the PVE ranging from 2.97% to 33.29% with an average value of 18.20%, 3 with the PVE ranging from 5.23% to 29.85% with an average value of 18.28%, 6 with PVE ranging form 13.84% to 22.15% with an average 17.56%, and 4 with PVE ranging form 15.87% to 38.52% with an average 26.24%, respectively.