马氏珠母贝选育系遗传变异的AFLP分析

利用AFLP技术对马氏珠母贝两个选育系DDS-G1和JCS-G1及大亚湾养殖群体(DDC)进行了遗传变异分析.5对选择性扩增引物共扩增谱带265条,DDC的多态位点比率为79.25%,DDS-G1为73.58%,JCS-G1为75.85%.两个选育系的单态位点明显增加,而Shannon's遗传多样性指数和Nei's基因多样性有所下降.三个组间的遗传距离为0.1615～0.2744,两个选育系间的遗传距离较大.研究结果表明,经过一代的选择,马氏珠母贝选育系的遗传结构和遗传多样性已发生改变,AFLP标记能够有效地监测选育系的遗传变异.

Study of genetic variation in the selected stocks of Pinctada martensii Dunker by AFLP

Amplified fragment length polymorphisms (AFLPs) markers were used to examine genetic variation in 2 selected stocks (DDS-G1 and JCS-G1) and one non-selected control stock (DDC) of the pearl oyster Pinctada martensii Dunker. A total of 265 bands were generated by 5 pairs of AFLP primers combinations, among them 79.25%, 73.58% and 75.85% were polymorphic in DDC, DDS-G1 and JCS-G1 respectively. There was an increase of monomorphic loci in DDS-G1 and JCS-G1 compared with DDC. Moreover, the reduction of Shannon's information index and Nei's gene diversity were observed in the selected stocks. Average genetic distance among three groups varied from 0.1615 to 0.2744, with greater genetic distance between two selected stocks. The result of this study shows that AFLP is sensitive to detect the genetic variation of pearl oyster, and the genetic structure and genetic diversity of two stocks have been changed when subjected to one generation of selection.