马氏珠母贝3个野生种群及种群间杂交后代遗传多样性的ISSR分析

运用ISSR分子标记技术分析了马氏珠母贝(Pinctada martensii)广西北海(BW)、广东大亚湾(DW)和海南三亚(SW)野生种群及其自繁子一代(BB1、SS1、DD1)和杂交子一代(BS1、BD1、DS1)9个群体各50个个体的遗传多样性.结果表明:3个野生群体遗传多样性分别是0.2585、0.2607和0.2571;3个自繁群体子一代遗传多样性分别是0.2504、0.2545和0.2527,3个杂交子一代遗传多样性分别是0.2747、0.2659和0.2784.种群间杂交增加了子代的遗传多样性,同时增加了杂交子一代与杂交亲本间的遗传距离,而自繁群体的遗传多样性与其来源的野生种群比较,遗传多样性降低.本文指出利用野生群体进行杂交育种应该纯化亲本才能获得杂种优势,人工育苗或选择性育种需要保持足够数量的繁殖亲本以避免遗传多样性降低.

Genetic diversity of three popultions and the first generations of hybridization between different populations of pearl oyster, Pinctada martensii (dunker)

ISSR,the inter-simple sequence repeats was applied to investigate the genetic diversities of three wild population of pearl oyster;Pinctada martensii(Dunker),the wild populations from Beihai(BW),Daya Bay (DW) and Sanya(SW).The genetic diversity index of BW,DW and SW were 0.2585,0.2607 and 0.2571 respectively.Three first generations of hybridization between wild population were produced,BD1,from BW and DW,BS1 from BW and SW,DS1 from DW and SW.At the same time,three first generations of mating in each wild population were also produced,BB1 from BW,DD1 from DW,and SS1 from SW.The genetic diversity index of hybridizing generation,BD1,BS1 and SD1 was 0.2659,0.2747 and 0.2784 respectively.BB1,DD1 and SS1 had its diversity index,which was 0.2504,0.2527 and 0.2545.To get heterosis from hybridization between populations,genetic traits of parents need to be purified.Genetic diversity in self-mating population was lower than that of corresponding wild population.It suggested that keeping effective population size was very important to avoid inbreeding in cultured breeding and selective breeding.