利用SRAP标记分析3个团头鲂群体的遗传多样性

Genetic Diversity of Three Populations of Blunt Snout Bream (Megalobrama amblycephala) Analyzed by SRAP Markers

采用SRAP（sequence-related amplified polymorphism）分子标记,对长江中下游地区淤泥湖、梁子湖、鄱阳湖的3个团头鲂自然群体的遗传多样性进行了分析。从88对引物组合中筛选出13对条带清晰、多态性丰富的引物组合,每对引物组合检测到的位点数为8-21个,在3个团头鲂群体中共检测到172个位点。鄱阳湖群体的多态位点百分率（58.14%）、Nei＇s基因多样性（0.1849）和Shannon＇s信息指数（0.2799）最高,梁子湖群体的多态位点百分率（51.16%）、Nei＇s基因多样性（0.1524）和Shannon＇s信息指数（0.2347）次之,淤泥湖群体的多态位点百分率（29.07%）、Nei＇s基因多样性（0.0904）和Shannon＇s信息指数（0.1371）最低。3个团头鲂群体中,鄱阳湖群体遗传多样性最高,淤泥湖群体最低。3个群体间的Nei＇s无偏遗传距离为0.0866-0.2207,遗传相似度为0.8020-0.9170;鄱阳湖和淤泥湖群体间遗传距离最大（0.2207）,亲缘关系较远,鄱阳湖和梁子湖群体间遗传距离最小（0.0866）,亲缘关系较近。

To provide genetic background on germplasm of blunt snout bream（Megalobrama amblycephala）,SRAP（sequence-related amplified polymorphism）markers were used to investigate genetic diversity of three natural populations of M.amblycephala from Yuni Lake,Liangzi Lake and Poyang Lake in the middle of the Yangtze River drainage.Thirteen pairs of primer combinations,which were screened from 88 primer pairs,produced clear and polymorphic bands and were used for SRAP amplification.The numbers of amplified loci per primer pair ranged from 8 to 21,and a total of 172 loci were detected in three populations.Of which,percent of polymorphic loci（P）,Nei＇s gene diversity（h）and Shannon＇s information index（I）were the highest in Poyang population（P =58.14%,h=0.184 9,I=0.279 9）,followed by Liangzi population（P =51.16%,h=0.152 4,I=0.234 7）and Yuni population（P=29.07%,h=0.090 4,I=0.137 1）.The genetic diversity was the highest in Poyang population and was the lowest in Yuni population.The Nei＇s unbiased genetic distance and genetic identity among the three populations was from 0.086 6 to 0.220 7 and from 0.802 0 to 0.917 0,respectively.UPGMA cluster analysis showed that there was farther genetic relationship between the Poyang and the Yuni populations with the most genetic distance（0.220 7）,and closer genetic relationship between the Poyang and the Liangzi populations with the least genetic distance（0.086 6）.