木薯栽培品种农艺性状与分子标记的关联分析

为寻找与木薯茎叶鲜重、块根鲜重、株高、开花、块根数和叶片叶绿素含量紧密关联的分子标记,利用145对SRAP,132对EST-SSR引物对19个木薯栽培品种进行多位点的扫描分析,并在分析群体的连锁不平衡水平基础上,通过关联分析软件TASSEL2.1将标记与这些栽培品种的以上农艺性状进行关联。结果表明:群体中非共线性的SRAP和EST-SS位点组合存在一定的连锁不平衡,在147个SRAP位点的1471个位点组合中支持的不平衡成对位点仅在木薯粗略基因组中占位点组合的0.815%(p0.01),132个ESTSSR位点的993种位点组合仅在木薯基因组中占位点组合的0.302%(p0.01);利用EST-SSR数据分析栽培品种的群体结构可划分为3个亚群,亚群的划分与群体亲缘类型相关联;共检测到29个与性状相关联的位点,其中与茎叶鲜重相关的位点11个,与块根鲜重相关的位点3个,与株高相关的位点3个,与是否开花相关的位点8个,与块根数相关的位点5个,与叶片叶绿素含量相关的位点2个。下一步工作是进行优等位基因的挖掘,找到与茎叶鲜重和株高相关的优异位点、等位变异及携带优异等位变异的载体材料。

Association Analysis between Agronomic Traits and Molecular Markers in Cassava

The aims of this study were to investigate the molecular markers closely associated with cassava agronomic traits including fresh weight of shoots and tuberous-roots, plant height, flowering, the number of tuberous roots and leaf-chlorophyll content. The genomic regions with selection sweep were detected through scanning 19 cassava cultivars using 145 SRAP markers and 132 EST-SSR markers. The agronomic traits described above linked with these regions were analyzed using marker-trait association analysis based on the linkage disequilibrium(LD) by the software TASSEL GLM(General linear model). The results indicated that (1) LD was detected in nonsynteic markers, while the loci pairs with p<0.01 accounted for only 0.815% of the total 1471 SRAP loci and 0.302% of the total 993 SRAP loci;(2) Genetic structure analysis showed that cultivar population was composed of 3 subpopulations, which were associated with their relationship-types and(3) 29 loci associated with the agronomic traits were detected, in which 11 loci were correlated with fresh weight of shoots, 3 loci with fresh weight of tuberous roots, 3 loci with plant height, 8 loci with flowing, 5 loci with the number of tuberous roots and 2 loci with leaf-chlorophyll content.