长毛明对虾野生群体的杂合性研究

应用聚丙烯酰胺凝胶电泳技术，研究了长毛明对虾（Fenneropenaeus penicillatus）9个野生群体杂合子缺乏及过量情况；测定了8个酶系统，共检测到15个酶位点和32个等位基因．有7个多态位点，它们是Me-1、Me-2、Mdh-2、Aat-1、Sod-2、Est-1、Amy-1位点，在这些位点有2～5个等位基因．结果表明，在长毛明对虾9个群体的全部多态位点中，共有6个位点符合哈温平衡（P〉0．05），30个位点偏离哈温平衡（p〈0．05）；除宁德群体外，其他8个群体中共有13个多态位点表现为杂合子缺失，结合每个群体中各个多态位点的期望杂合度与观察杂合度，认为导致杂合子缺乏的主要原因可能是种群内交、自然选择、Wahland效应、哑等位基因等．另外，在本研究中共有23个位点表现为杂合子过剩（F〈0），且在长毛明对虾9个群体中均有出现，从而认为长毛明对虾的种质资源较好．

Heterozygosity in wild populations of Fenneropenaeus penicillatus

Heterozygosity was investigated using the assay of vertical slab polyacrylamide gel electrophoresis in 9 populations of Fenneropenaeus penicillatus.Allozyme is co-dominant and can be analyzed under standard Hardy-Weinberg model.Allozyme electrophoresis is considered to be a critical useful technique in population genetics.Eight enzymes presumably encoded by 15 allozyme loci and 32 alleles were scored in F.penicillatus.Seven loci with 2～5 alleles are polymorphic.They are Me-1,Me-2,Mdh-2,Aat-1,Sod-2,Est-1,Amy-1.Results also showed that 6 loci of the total polymorphic loci in F.penicillatus were found to be in agreement with those expected from the Hardy-Weinberg equilibrium(p>0.05),while the other were found to depart clearly from those expected from the Hardy-Weinberg equilibrium(p<0.05).Except for Ningde Population,heterozygote deficiency existed in 13 polymorphic loci from the other 8 populations of F.penicillatus.Taking the observed heterozygosity (H_o) and the expected heterozygosity (H_e) of the population into consideration,the main reasons that lead to the heterozygote deficiency may be inbreeding,presence of null allele,Wahland effect and natural selection.Besides,heterozygote excess exists in 23 loci(F＜0) from the 9 populations of F.penicillatus,which indicated that the germplasm resource of F.penicillatus is in good conditions.