日本沼虾太湖和鄱阳湖群体及其F1的遗传结构分析

Genetic structure analysis of parents and F1 generation groups of Macrobrachium nipponense from Taihu Lake and Poyang Lake

摘要:

采用12对微卫星标记分析了日本沼虾太湖、鄱阳湖两个野生群体及其双列杂交的F₁的遗传结构和遗传多样性。结果显示，所用引物的平均等位基因数(N_a)为17.67个，有效等位基因数(N_e)为12.48个，大小在112～427 bp之间。平均观测杂合度(H_o)为0.693 8，平均期望杂合度(H_e)为0.913 4。2个亲本及4个子代组合的两两遗传分化指数F_ST值在0.020 5~0.042 7之间，基因流(N_m)数值在5.607 5~11.957 0之间，表明日本沼虾组合间分化不明显。聚类分析结果表明，TP（太湖♀?鄱阳湖♂）组合与PT（鄱阳湖♀?太湖♂）组合，TT（太湖♀?太湖♂）组合与TH（太湖亲本）组合，PP（鄱阳湖亲本）组合与PY（鄱阳湖♀?鄱阳湖♂）组合分别先聚在一起，之后是TP，PT，TT，TH组合聚在一起，最后再与PP，PY组合聚合在一起。试验结果显示，杂交组合的观测杂合度有明显提高；杂交组合与其它组合分化不明显；杂交子代与母本的遗传结构更相似。本试验通过杂交来分析亲本及子代各个组合之间遗传多样性及遗传结构的变化情况，为日本沼虾资源保护和开发利用提供理论依据。

Abstract:

Genetic diversity and genetic structure of Macrobrachium nipponense (parents from Taihu Lake and Poyang Lake, F₁ generations from diallel crosses) were analyzed by using 12 pairs of microsatellite markers primers selected. The results showed: the average number of alleles (N_a) for 17.67 and effective alleles (N_e) for 12.48, between 112-427 bp in size. Average observed heterozygosity (H_o) for 0.693 8, and mean expected heterozygosity (H_e) for 0.913 4. Six stocks had genetic differentiation index F_ST value between stocks in 0.023 4-0.052 9, and gene flow (N_m) in 4.476 6-10.411 7. The differentiation is not obvious. Clustering analysis results showed that TP (Taihu Lake ♀?Poyang Lake ♂) stock and PT (Poyang Lake ♀?Taihu Lake ♂) stock, TH (Taihu Lake parents) stock and TT (Taihu Lake ♀?Taihu Lake ♂) stock, PY (Poyang Lake parents) stock and PP (Poyang Lake ♀?Poyang Lake ♂) stock were gathered, respectively, and then, TP, PT, TT and TH gathered again, finally, with PY and PP gathered. Test results showed that observed heterozygosity of the hybrid stocks had increased obviously, but there was no obvious differentiation between hybrid stocks and other stocks. Furthermore, the hybrid progenies were more similar to the female parent in genetic structure. In this study, we analyzed genetic diversity and genetic structure between various stocks by hybridization for Macrobrachium nipponense, so as to provide theory basis for resources conservation and exploitation.