高丹草茎叶等农艺性状的QTL定位

QTL Mapping Analysis of Agronomic Traits such as Stem and Leaf of Sorghum-Sudangrass Hybrid

以散穗高粱×红壳苏丹草杂种F2代305个分离单株群体为材料,在前期已构建出的高丹草高密度AFLP分子标记遗传图谱上,采用MQM模型法对茎粗、叶片数、叶长、叶宽、穗长、穗宽、分蘖数共7个农艺性状进行了QTL定位分析。结果表明:7个性状三年一点测定的平均值均呈正态分布,适合于QTL定位分析;在LOD>2.5条件下,7个性状共定位了63个QTL,分布在10个连锁群上,其遗传贡献率变幅在8.8%~44.4%之间。在63个QTL中,控制茎粗的QTL有13个,控制叶长的有11个,控制分蘖数的有10个,控制穗宽的有16个,4个性状的QTL在10个连锁群上均有分布;控制叶宽的QTL有2个,分布在LG4连锁群上;控制穗长的有2个,分别位于LG2和LG3连锁群上;控制叶片数的QTL有9个,其分别位于LG1、LG2、LG3、LG4、LG6、LG8、LG10连锁群上。

To provide the basis for the further study of fine mapping,map-based cloning and molecular assisted breeding of important straits such as yield and quality of Sorghum-Sudangrass hybrid,305F2 individuals from a cross of Sorghum bicolor × Red hull sudangrass were used as a mapping population,and the QTLs for seven agronomic traits such as leaf number,leaf length,leaf width,panicle length,panicle width,stem diameter and tiller number were identified using MQM QTL models,on the basis of the previously constructed high-density genetic linkage map of Sorghum-Sudangrass hybrid.The results showed that the average measurements of seven agronomic traits in three years of one location showed a normal distribution,which were suitable for QTL analysis.Under the conditions of LOD〉 2.5,a total of 63 QTLs for seven agronomic traits were identified,and distributed in 10 linkage groups,which explained the variation from 8.8%to 44.4%.Of all the QTLs,a total of 13 QTLs controlled stem diameter,11 QTLs controlled leaf length,10 QTLs controlled tiller number,16 QTLs on all the 10 linkage groups controlled panicle width,two QTLs on LG 4controlled leaf width,two QTLs on LG 2and 3controlled panicle length,and nine QTLs on LG1,2,3,4,6,8and 10 controlled leaf number.