Study on genetic diversity of cultivated populations in 4 species of shrimps

Genetic diversity of cultivated populations was investigated using assay of vertical slabpolyacrylamide gel electrophoresis in 4 species of shrimps, which were Penaeus japonicus, Penaeus monodon , Penaeus vannamei and Metapenaeus ensis, The results showed that the mean number of alle-les per locus (A) is 1.3±0.2, 1.3±0.1, 1.3±0.1 and 1.3 ±0.1 respectively; the percentage of polymorphic loci (P0.95) is 12.5, 6.7, 20 and 23.5 respectively; the expected heterozygosity (He) is 0.042±0.034,0.042±0.031, 0.094±0.042 and 0.097±0.047 respectively; and the observed heterozygosity (H0)is 0.029±0.024, 0.028±0.023,0.154±0.082 and 0.150±0.084 respectively. The difference of genetic diversity is obvious in 4 species of shrimps. The degree of genetic diversity is M. ensis > P. vannamei > P. japonicus > P. monodon. In short, the lower level of genetic diversity is estimated in 4 species of shrimps.

几种优良养殖对虾杂合性的比较研究

应用聚丙烯酰胺凝胶电泳技术研究了南美白对虾(Penaeusvannamei)、日本对虾(Penaeusjaponicus)、斑节对虾(Penaeusmonodon)、新对虾(Metapenaeusensis)养殖群体杂合体缺乏及过量。结果表明南美白对虾在Est-2(F=0.705),Aat-2(F=1.000)两个位点上存在杂合子缺乏,在Adh -3(F= -1.000),Sdh -2(F= -1.000),Mdh -4(F= -1.000)三个位点上存在杂合子过量;日本对虾在Est-1(F=0.258),Sod -1(F=0.467)两个位点上存在杂合子缺乏;斑节对虾在Est-1(F=0.254),Sdh -3(F=1.000)两个位点上存在杂合子缺乏;新对虾在Aat-1(F=1.000)位点上存在杂合子缺乏,在Est-1(F= -0.158),Sod -1(F= -1.000),Me -4( -F=1.000)三个位点上存在杂合子过量。导致杂合子缺乏的主要原因可能是自然选择、近交、Wahland效应等。杂合子缺乏会导致某些基因从基因库中消失,造成种群遗传多样性的降低 ,从而降低物种适应环境的能力。