短蛸(Octopus ocellatus)四个地理群体遗传特性的AFLP分析

THE GENETIC DIVERSITY OF OCTOPUS OCELLATUS BY AFLP MARKERS

应用AFLP标记技术对我国北方近海短蛸的遗传多样性进行分析。采用6对AFLP引物组合对4个群体(大连、烟台、青岛、连云港)120个个体进行扩增,其中每对引物扩增位点数在42—66之间,共得到303个扩增位点。4个群体内的多态位点比例为62.03%—67.93%。群体的Nei’s基因多样性指数(H)为0.2353—0.2617,Shannon多样性指数(I)为0.3497—0.3863,群体间的遗传距离为0.0497—0.085;大连群体的多态位点比例、Shannon多样性指数和群体Nei’s基因多样性指数均高于其它三个群体。用UPGMA方法构建的群体系统进化树显示,大连群体与烟台群体聚到一起,青岛群体与连云港群体聚到一起,显示群体间具有典型的地理特征,但群体间存在遗传渗透。分子变异分析(AMOVA)结果表明,短蛸群体88.28%的变异来源于群体内,群体间的变异占11.72%,显示短蛸的遗传变异主要来源于群体内个体间,但群体间已经有了一定程度的遗传分化。

Amplified fragment length polymorphism （AFLP） was applied to assess the genetic variation among four populations of Octopus ocellatus, the four populations included Dalian （DL）, Qingdao （QD）, Yantai （YT）, and Lianyungang （LY）. A total of 303 reproducible bands amplified with 6 AFLP primer combinations were obtained from 120 individuals. The percentage of polymorphic loci ranges from 62.03% to 67.93% within the four populations. The Nei’s gene diversity （H） of the four populations are 0.2353—0.2617. The Shannon diversity indices （I） are 0.3497—0.3863, and the genetic distances （D） are 0.0497—0.085 among populations. The percentage of polymorphic, loci （P）, Shannon diversity index, genetic distance for the population DL is the highest among the four populations. The four populations are clustered into two major clades by UPGMA method based on genetic distance. Populations of DL and YT are clustered into one clade, QD and LY are clustered into the second clade, showing typical geographical features among the four groups. Although the four populations are grouped into two clusters by whole population, all the 120 individuals from four populations are not clustered with each other. AMOVA analysis indicates that 11.72% of variance is inter-populations and 88. 28% of variance is intra-populations, showing the genetic variation occurred mainly within groups; however, certain degree of genetic differentiation took place among groups.