凡纳滨对虾6个养殖群体遗传多样性的比较分析

中国多批次引进凡纳滨对虾Litopenaeus vannamei并结合生产开展了相对独立的育苗工作，但对引进群体及引进后留种形成的本地群体的遗传变异水平缺乏了解，不利于种质管理及利用。此研究采用AFLP技术对抽查的6个养殖群体进行分析，发现进口群体具有相对较高的遗传多样性水平；养殖性能较好的东方、海星和旭明群体遗传多样性水平与进口群体相近；而乾塘群体遗传变异水平最高，推测可能是与其种质混杂有关；广益群体遗传多样性水平最低，可能已出现近交衰退。通过对各个群体间的遗传距离进行分析，为下一步根据亲缘关系的远近开展群体问杂交育种提供技术依据。

Analysis on genetic diversity of six cultured stocks of Litopenaeus vannamei

Many batches of Litopenaeus vannamei were introduced to China and used as broodstocks to reproduce relatively independently.Analysis on genetic diversity of six cultured stocks in south China revealed that genetic diversity level of the stock introduced from Hawaii was relatively high,and Dongfang,Haixing and Xuming stocks were close to the introduced one.Genetic diversity level of Qiantang stock was the highest compared with that of Dongfang,Haixing,Xuming,and Guangyi stocks,suggesting that Qiantang stock was contaminated by other stocks.Genetic diversity level of Guangyi stock was the lowest,suggesting inbreeding depression.Genetic distance among stocks was evaluated and a dendrogram tree was constructed using UPGMA method,which could be useful for selection of distant broodstocks for outbreeding in the near future.