山东沿海褶牡蛎与太平洋牡蛎等位基因酶的遗传变异

采用水平淀粉凝胶电泳技术研究了山东沿海莱州 (LZ)、俚岛 (LD)和青岛 (QD)三地褶牡蛎自然群体以及荣成的太平洋牡蛎 (TP)养殖群体的等位基因酶遗传变异。进行测试的 9种酶中共检测到 2 0个位点。LZ与QD群体的多态位点比例为 6 0 .0 % ,其余两群体均为 5 5 .0 %。LZ、LD、TP和QD各位点平均有效等位基因数分别为 1.42 2± 0 .16 5、1.2 38± 0 .0 85、1.2 0 7± 0 .0 86和 1.32 6± 0 .119。平均杂合度观察值分别为 0 .2 16± 0 .0 5 0、0 .16 5± 0 .0 36、0 .139± 0 .0 34和 0 .195± 0 .0 42。结果表明 ,LZ和QD群体的遗传变异水平高于LD和TP群体。同时 ,各群体中普遍存在杂合子缺失现象。太平洋牡蛎群体与其它三个褶牡蛎群体的遗传距离很小 ,甚至小于莱州和青岛的两个褶牡蛎群体间的遗传距离 0 .0 5 0 0 ,尤其是与俚岛褶牡蛎群体遗传相似度最大 ,遗传距离小于其它各群体之间的距离 ,仅为 0 .0 0 99。

Allozyme variation within Crassostrea plicatula and Crassostrea gigas from Shandong coastal waters

Allozyme variation within three natural populat ions of Crassostrea plicatula from Shandong coastal waters ( LZ, LD and QD ) and one cultured population of C. gigas from Rongcheng ( TP) were investigated by horizontal starch gel electrophoresis. 20 loci were detected in 9 enzymes. The percentages of polymorphic loci were 60% in LZ and QD populations and 55% in the other two. High variation was shown in LZ and QD populations. Mean heterozygosity observed in LZ, LD, TP and QD was 0. 216 ? 0. 050, 0. 165 ? 0. 036, 0. 139 ? 0. 034 and 0. 195 ? 0. 042 respect ively. Mean effect ive number of alleles varied from 1. 207 ? 0. 086 to 1. 422 ? 0. 165. More genetic variations were shown in LZ and QD populations than in LD and TP populations. Heterozygous deficiency was common in all populations. Nei distance between TP and the other three populations of C. plicatula were very similar to each other, but the largest one still below that of LZ and QD ( 0. 0500) . The smallest Nei distance was between LD and TP populations( 0. 0099) . The research indicated that C. plicatulaand C. gigas might belong to the same species of C. gigas .