中国沿海管角螺4个自然群体遗传多样性的RAPD分析

RAPD analysis on Hemifusus tuba(Gmelin) of four different natural populations in China

利用RAPD技术对管角螺(Hemifusus tuba Gmelin)4个自然群体(广西北海、广东湛江、浙江温州、江苏连云港)的遗传多样性进行了分析。所选择的19条有效引物在4个自然群体200个个体中总共产生182个扩增片段,片段数量为19 983个,片段大小在250～2 500 bp之间。其中每条引物可产生4～17条带,平均5.28个位点。4个自然群体共检测到149个多态位点,多态位点比例为81.87%,其中北海群体的多态位点比例最高,占66.48%,其次是湛江群体为47.25%,温州群体为44.51%,连云港群体为36.81%。4个群体中均未检测到各群体特有的扩增带。4个自然群体管角螺的Nei’s指数和Shannon指数表现为一致性,表明遗传多样性在4个自然群体的大小为北海群体>湛江群体>温州群体>连云港群体。4个自然群体的遗传距离在0.054 2～0.137 4之间。基于群体间遗传距离的值进行聚类分析,结果表明,4个群体中,北海与湛江群体首先聚在一起,温州与连云港群体随后聚在一起,最后4个群体聚在一起。研究亮点:利用RAPD技术首次对我国管角螺4个不同分布区自然群体的DNA多态性进行种内遗传差异分析,并探讨其遗传多样性和地理分化特征。结果表明,管角螺4个自然群体目前尚保持了较高的遗传多样性,但环境污染和不合理的捕捞方式都可导致遗传多样性的降低。管角螺的遗传变异主要来自群体内个体间,少部分存在群体间,各群体具有较大的遗传变异潜力。

Nineteen RAPD primers amplified a total of 182 scorable markers in 200 samples from the four different natural populations of H.tuba,thus a total of 19 983 bands which ranged in size from 250 to 2 500 bp were generated showing homogeneous RAPD patterns,and number of scorable bands for each primer varied from 4 to 17 with an average of 5.28 bands per RAPD primer.81.87% of the total genetic diversity was found among the four populations which contained approximately 149 polymorphic loci.66.48%,47.25%,44.51%,36.81% of the total genetic diversity were attributable to genetic differences within Beihai,Zhanjiang,Wenzhou,Lianyungang populations.Estimates of Nei’s Gene Diversity and the Shannon’s Diversity Index provided similar results of diversity,from high to low,that is,Beihai,Zhanjiang,Wenzhou,Lianyungang populations.The cluster analysis of the four populations was based on Genetic Distance,which was measured between 0.054 2-0.137 4.The results showed the populations of Beihai and Zhanjiang first assembled one branch,Wenzhou and Lianyungang then assembled another,and the two branches assembled finally.