家蚕杂交分离系间的分子标记特征研究

以两个日系家蚕品种“湘晖”(P1)和“872”(P2)为亲本进行杂交,从F1自交的F2代开始,分别向茧丝量高和低两个方向进行选择。经过F2-F7共6代的同蛾区交配选择,获得了茧丝量性状有显著差异的A、C两个家系。用5组引物扩增所获得的617个AFLP分子标记,分析了A、C两个杂交分离系的分子标记特征及其DNA多态性。结果显示P1能将更多的标记传给C系,亲本P2能将更多的标记传给A系,A系保留了更多的两亲共有的标记;A系含较稳定的特异性标记23个,C系含特异性标记7个,推测A系的这些特异性标记与家蚕某些经济性状有关;通过杂交分离系各世代的遗传距离和聚类分析,F6代同一家系内差异更小,A系与C系家系间的差异更加明显,即同蛾区交配到F6代系统就基本稳定。

The Character of Molecular Markers Between Segregation Lines of Hybridization in Silkworm Bombyx mori

With the Japanese line “Xianghui”and “872” as the parents, the offspring after F_2 was selected according to high (A line) or low (C line) cocoon silk amount respectively. Two strains A and C, which have significant differences in cocoon silk trait, were obtained by selection from F_2 to F_7. 617 molecular markers were obtained by AFLP from 5 primers. The molecular marker and DNA polymorphisms of two strains were analyzed. The results showed that C strain tends to like P_1, while A strain tends to like P_2, and that A strain has more common markers with parents. A strain had 23 specific markers, and C strain had 7 specific markers. The specific markers of A strain maybe relative to some economic quantitive traits of silkworm. The dendrogram by UPGMA suggested that it is less diversity among the individuals of F_6 generation of same strain, and more diversity between different strain. Which suggested that the strain is stable in heredity while mating is within the same batch till F_6 generation.