不同苗种来源的中国虾夷扇贝群体的遗传多样性分析

Study on the Genetic Diversity of Different Breeding Source of the Japanese Scallop(Mizuhopecten yessoensis) in China

虾夷扇贝(Mizuhopecten yessoensis)于1982年从日本引入中国并展开规模化养殖。由于引入的亲贝数目有限,使虾夷扇贝在人工育苗养殖过程中群体遗传多样性水平下降。本研究使用7对微卫星引物对日本原种贝(♀、♂)自交后的子代群体(RZ)、国内种贝(♀、♂)自交后的子代群体(DZ)、日本原种贝(♂)与国内种贝(♀)的杂交群体(ZH)和国内自然海区(中国旅顺月亮湾)天然繁殖群体(HC)4个不同的虾夷扇贝群体的遗传多样性进行了研究。实验结果表明,4个群体的平均有效等位基因数为3.2～3.8,平均期望杂合度为0.6718～0.7017,日本野生群体做为种贝繁殖的苗种(RZ)与中国养殖群体相比,遗传多样性水平较高,除了DZ群体外其他群体的遗传多样性并无显著的变化。

The Japanese scallop(Mizuhopecten yessoensis) was introduced form Japan to China in 1982.Because of the limited number of foundation population,the genetic variability has been lost during hatchery production.For restoring the generic diversity of Japanese scallop in China,some means and steps for seed yielding,such as re-introducing Japanese wild population from Japanese as parents or hybridizing Chinese hatchery population(♀) with Japanese wild population(♂),were adopted by hatching plant.In this study, seven microsatellite loci were used to investigate the genetic variations of four different populations,namely,one Japanese hatchery population which parents came from Japanese wild population,one hybrid population from Chinese hatchery population(♀) and Japanese wild population(♂),and to compare with one Chinese hatchery population and one natural seed population from Dalian in China.The average effective allele numbers per locus(Ae) of the above corresponding populations ranged from 3.2 to 3.8,the average expected heterozygosities (He) ranged from 0.6718 to 0.7017.These data explained that the seed breed from Japanese wild population as parents had obvious high level genetic diversity than the Chinese hatchery population,and except for the Chinese hatchery population,the genetic variations of the others had no obvious variance.