飘鱼微卫星位点的筛选及珠江流域5个地理群体的遗传多样性分析

为了解珠江流域飘鱼(Pseudolaubuca sinensis)群体间的遗传多样性及其分化程度, 利用RAD-Seq技术开发出微卫星位点, 并设计了100对微卫星引物, 筛选出66个可稳定扩增出目的条带的位点, 其中16个具有较高的多态性(PIC>0.5), 以2碱基重复居多。利用其中10对多态性位点对珠江流域的郁江(YuJ)、左江(ZJ)、右江(YJ)、融江(RJ)和桂江(GJ)飘鱼群体进行遗传多样性研究, 得到有效等位基因数、观测杂合度、期望杂合度范围分别为5.2028—6.3800、0.6773—0.7667和0.7975—0.8425, 表明珠江流域5个飘鱼群体具有较高的遗传多样性, 以YuJ群体遗传多样性最高, RJ群体遗传多样性为最低。且群体间各个遗传参数相差较小, 说明他们的遗传多样性水平相近。AMOVA分析显示, 遗传变异主要来自于群体内(98.45%), 仅一小部分的变异来自于群体间(1.55%), 总群体的遗传分化系数F_st为0.015, 两两群体间的F_st在–0.0033—0.0295波动, 属于低等程度的分化。群体间基因交流值(N_m)在8.2246—76.0075, 表明群体间基因交流频繁, 对遗传漂变作用的抵制能力较强。研究筛选出了多态性高的微卫星位点, 并利用其对5个飘鱼群体遗传多样性进行评价, 旨在有效地监测飘鱼的种质资源状况, 为其资源的开发利用和保护提供科学指导。

MICROSATELLITE PRIMERS SCREENING AND GENETIC DIVERSITY ANALYSIS OF FIVE GEOGRAPHICAL POPULATIONS OF PSEUDOLAUBUCA SINENSIS IN THE PEARL RIVER BASIN

To explore the genetic diversiy and diffentation degree of Pseudolaubuca engraulis population in the Pearl River Basin, RAD-Seq technology was used to develop microsatellite loci. A total of 100 pairs of microsatellite primers were designed, 66 of which could stably amplifiy the target band, including 16 polymorphic microsatellite markers (PIC>0.5) which were mostly with 2 base repeats. Ten polymorphic microsatellite loci were used in genetic diversity analysis in five P. sinensis populations of Pearl River Basin (YuJ, ZJ, YJ, RJ, GJ). The effective allele number, observed heterozygosity, and expected heterozygosity varied from 5.2028—6.3800, 0.6773—0.7667, and 0.7975—0.8425, respectively. The results showed that five P. sinensis populations in the Pearl River Basin had a high level of genetic diversity level, the YJ population had the highest genetic diversity while the RJ population had the lowest. The genetic parameters of population differed little, indicating that their genetic diversity level was close. AMOVE analysis showed that the genetic variation mainly come from population (98.45%), and only a small part of the variation came from different population (1.55%). The genetic differentiation coefficient F_st of the total population was 0.015, which was a low degree of differentiation. The gene exchange value (N_m) was between 8.2246 and 64.3526. The results showed that there were frequent gene exchange in different populations and strong resistance to genetic drift. This study screened microsatellite loci with high polymorphism and used the loci to evaluate the genetic diversity of the P. sinensis population, aiming to effectively monitor the germplasm resources of P. sinensis and to provide scientific guidance for its resource development, utilization and protection.