基于核基因的黄绿卷毛菇系统发育与谱系地理学分析

Phylogenetic and Phylogeographic Analysis of Floccularia luteovirens Based on rDNA Fragmets

黄绿卷毛菇(Floccularia luteovirens)隶属于伞菌目(Agaricales)口蘑科(Tricholomataceae)是一种主要分布在青藏高原的产子实体的外生菌根真菌。本研究以青藏高原黄绿卷毛菇(F.luteovirens)的23个野生居群,404个个体为研究对象,利用rDNA三个片段(ITS+5.8 s,IGS-1以及LSU)研究了青藏高原黄绿卷毛菇种內的系统发育关系。研究表明:联合序列共获得15种基因型,基因型多样性(h)的范围从0.374 3(MD)到1.000 0(DR),平均值为0.723 3。歧点分布分析走势呈现单峰曲线,表明黄绿卷毛菇居群近期经历过扩张过程。对黄绿卷毛菇基因型变异的分布模式进行验证,得到NST>GST(p<0.05),表明黄绿卷毛菇基因型之间具有显著地分子系统地理结构。分子变异分析(AMOVA)表明,黄绿卷毛菇的遗传变异主要存在于居群内部(79.17%)。基于MP树和ML树的研究发现基因型H3、H4、H5、H15首先和其他基因型分开,而在贝叶斯分析中则不存在这一分支。没有一个居群拥有特有的基因型,但是就基因型多样性地域分布格局来看,各个基因型的多样性由北向南呈明显的减少趋势。结合软件NETWORK的分析可以知道,几种主要分布在阿尼玛卿山以南的基因型都位于网路结构的边缘,说明这几种基因型是较晚形成的。本研究是对之前利用蛋白质编码基因研究的很好地补充。

The Floccularia luteovirens is a species of mushroom in the Tricholomataceae family which is mainly distributed among Qinghai-Tibetan plateau.In the present study,we investigated phylogenetic relationships between 404 individuals from 23 wild populations of F.luteovirens using rDNA fragments(ITS+5.8 s,IGS-1 and LSU).The research show that:15 gene types were generated,the value of genetic diversity(h)ranged from 0.374 3(MD)to 1.000 0(DR),with mean value of 0.723 3.The mismatchdistribution over all the studied populations was found to be unimodal indicated a recent expantion.Permutation test showed that NST(0.485)was significantly greater than GST(0.211),indicating a clear phylogeographical structure.AMOVA analysis suggested that 79.17%of the total molecular variance was attributable within-population diversity(p<0.001).The MP tree and ML tree showed that F.luteovirens can be divided into two clusters,the first cluster included the genetypes H3,H4,H5,H15.However,under the Bayes tree,there was no such cluster.There was no population with unique genetype,meanwhile,the genetype diversity becomes lower and lower from northern to southern in eastern Qinghai-Tibetan plateau.This indicated that the ancient population expansion occurred from the northeast of Qinghai-Tibetan plateau and the NETWORK analysis also well confirmed it.This study is supplementary for former researches.