用SSR标记检测杂交籼稻三系亲本的遗传差异

随机选用分布于水稻(Oryza sativa L.)12条染色体上的110对引物,共筛选出26对具有多态性的SSR引物,对24份杂交籼稻三系亲本材料进行遗传多样性和亲缘关系分析.全部24份亲本中共检测出116对等位基因,每个SSR引物可检测到的等位基因数目为2～7个不等,平均每对引物可以检测到4.4个等位基因.多态信息量(PIC)的变动范围为0.068 9～0.803 6,平均PIC值为0.603 4;期望杂合度(He)的变动范围为0.081 6～0.829 8,平均值为0.616 9;多样性指数(1)变幅为0.173 2～1.791 3,平均为1.160 0.对供试亲本材料根据遗传距离进行UPGMA聚类分析,结果表明,SSR微卫星标记可以将24份亲本材料分为3个大群,各组亲本间的遗传差异较大.通过分子标记辅助育种,可以有效地鉴定供试亲本材料之间的亲缘关系,分析预测新种质材料的遗传差异,可作为选育强优势组合杂交水稻的重要参考指标之一.图2表3参24

Genetic Variation of Three-line Parents of Indica Hybrid Rice Detected with SSR Markers

Totally, 24 three-line parents of indica hybrid rice (Oryza sativa L.) were used to analyze their genetic diversity and genetic relationship by using 26 polymorphous primer pairs selected from 110 SSR (Simple sequence repeats) which dispersed on 12 chromosomes in rice. Those primers detected 116 alleles from all the 24 parents. The alleles number might range from 2 to 7 with an average of 4.4. The PIC (Polymorphism index content) value of the polymorphic markers ranged from 0.068 9 to 0.803 6, with average of 0.603 4. The expected heterzygosity (H_e) ranged from 0.081 6 to 0.829 8 and the average was 0.616 9. However, Shannon's information index (Ⅰ) ranged from 0.173 2 to 1.791 3 with average of 1.160 0. Furthermore, according to the results of cluster analysis by UPGMA method, the 24 parents materials were classified into three groups by microsatellite markers, and the parents among the groups showed relatively large genetic variation, which could be used to identify the relationship among the parents, and also to predict the heterosis of new materials by molecule markers assisted selection. The results provide a good reference to the choice of higher heterosis hybrid combinations in rice breeding. Fig 2, Tab 3, Ref 24