基于SSR分析的富民枳样本量对其遗传多样性指标的影响

为了对极小种群野生植物富民枳(Poncirus polyandra)采取合理有效的保护措施,采用SSR分子标记作为遗传完整性检测标记,研究不同梯度的有效样本量对微卫星分析中遗传多样性指标的影响。本研究利用5对SSR引物,对65份富民枳种质材料进行遗传完整性检测,并对富民枳种植资源遗传多样性的微卫星数据进行分析。结果表明:随着有效样本量的增加,有效等位基因数、观测杂合度、期望杂合度、多态性信息量和Shannon信息指数等遗传指标均随之增加,有效样本量与遗传多样性指标呈显著正相关。当以有效等位基因数、多态性信息量(PI,C)和Shannon多样性指数等来衡量时,有效样本量29株为曲线的拐点,此时代表了95%以上的遗传多样性水平;而以观测杂合度和期望杂合度来衡量时,有效样本量为25株时,便达到了该总体遗传多样性水平的95%以上。综合分析表明,富民枳的有效样本量以25~29株较为合适,目前富民枳的种质保存是合理有效的。

Effects of Poncirus polyandra Sample Size on Genetic Diversity Index by SSR Markers/

In order to take reasonable and effective protection of Poncirus polyandra,SSR markers was used as genetic integrity detection markers to study effective sample size of different gradient on genetic diversity index in microsatellite analysis.Five pairs of SSR primers were used to detect the genetic integrity of the 65 germplasm resources,and to analyze the genetic diversity of the germplasm resources.Results demonstrated that the effective sample size had significant positive correlation effects on genetic diversity index (effective number of alleles,observed heterozygosity,expected heterozygosity,polymorphic information content and Shannon's information index) of P.polyandra and the genetic diversity index increased with the increase of the effective sample size.When the effective number of alleles,polymorphic information content (PIC) and Shannon's information index were measured,the effective sample size was 29,which represented more than 95％ of the level of genetic diversity.When the effective sample size was 25,the total genetic diversity level was above 95％.The comprehensive analysis showed that the effective sample size of 25-29 was more suitable,and the germplasm conservation of P.polyandra was reasonable and effective.