马氏珠母贝(Pinctada martensii)四种壳色选育系F_5的生长及遗传多样性分析

GROWTH AND GENETIC DIVERSITY FOR FOUR SHELL COLOR LINES (F_5) OF THE PEARL OYSTER PINCTADA MARTENSII

采用跟踪测量和微卫星(SSR)技术研究了马氏珠母贝四种壳色选育系F5和对照组的存活率、生长情况及遗传多样性。结果表明,四种壳色选育系和对照组的生长性状之间均存在显著差异(P<0.05)。从30对微卫星引物中扩增筛选获得8个多态位点,多态位点比例为26.67%,它们在4个壳色选育系共120个个体中产生了42个等位基因,平均每个多态位点产生5.25个。4个选育系的平均期望杂合度范围为0.6622—0.6850,平均观察杂合度范围为0.2708—0.4667,平均多态信息含量PIC值范围为0.6025—0.6190,说明4个选育系的遗传多样性处于较高水平,具有育种潜力;平均遗传偏离指数均为负值,4个选育系均存在不同程度的杂合子缺失。遗传分化和遗传距离分析表明白壳色选育系与红壳色选育系之间的亲缘关系最近,黑壳色与白壳色之间的遗传距离最大。

Survival rate and growth traits were measured among four shell color lines and control group of the pearl oyster Pinctada martensii. Growth traits contained shell length, shell height, shell width, hinge line, body weight, tissue weight and shell weight. The result showed that significant variation existed in these groups. Genetic diversity of four shell color lines of P. martensii was analyzed using microsatellite DNA. 30 pairs of primers were designed for this research. The result shown that there were 8 polymorphic loci and the proportion of polymorphic loci was 26.67%. Total 42 alleles were observed at the 8 loci from 120 individuals, with an average of 5.25 alleles per locus. Average expected and observed heterozygosities were 0.6850, 0.6831, 0.6730, 0.6622 and 0.3750, 0.2708, 0.4667, 0.3208 for the four lines, respectively, which showed that high level genetic diversity and breeding potential existed in the four lines. Average polymorphism information contents were 0.6190, 0.6182, 0.6130, 0.6025, 0.6131, and D values of heterozygote deviation were -0.4526, -0.6036, -0.3065, -0.5156 for the four populations, respectively. Genetic differentiation and genetic distance analysis showed that white shell color line and red shell color line were genetically close while black shell color line and white shell color line were distant.