宁波长街缢蛏遗传结构的RAPD分析

Genetic structure analysis of the natural and the cultural stocks of Sinonovacula constricta in Changjie,Ningbo

利用RAPD技术对宁波长街自然群体和养殖群体缢蛏[Sinonovaculaconstricta(Lamarck)]的遗传背景进行了比较研究。21个引物共扩增出121条清晰可辨的RAPD标记 ,大小在250～2500bp之间 ,分别统计上述位点 ,得到两群体各遗传参数。结果表明 ,养殖环境对其影响较小 ,两者间遗传距离仅为0.0497,近交系数(Fst)为0.0735,有效繁殖个体数(Nem)为3.1514;两者平均遗传杂合度比较却发现养殖群体略大于野生群体 ,与其他的水产动物研究结果不同。作者推测上述结果与养殖缢蛏苗种来自天然采苗、无累代养殖和养殖区饵料较自然海区丰富等因素有关。

RAPD technique was explored to evaluate the genetic structure between natural and cultivated stock of Sinonovacula constricta distributed in Changjie of Ningbo.121distinguished RAPD sites,ranging from250bp to2500bp in size,were acquired with21decamer random primers.The statistic results,inclouding genetic distance,inbreeding co-efficient and available number for reproduction,informed us that the stock condition exerted little influence on their genetic structure.The values of the above genetic parameters were0.0497,0.0735and3.1514in turn.The heterozygosities was higher in cultivated stock than natural one,which was not consistent with any other reports in other aquatic animals.This may be due to the abundance bait and natural larva collecion.