七筋姑不同倍型的克隆构型研究

Clonal Structure of Different Cytotypes of Clintonia udensis

七筋姑隶属百合科七筋姑属,多年生草本,具有二倍体和四倍体两种细胞型,可通过根芽的方式进行无性繁殖.本文采用SSR分子标记对其克隆结构进行研究,结果表明:二倍体种群与四倍体种群全为多克隆种群,没有发现单克隆种群,克隆构型均为混合型.两种倍型152个七筋姑个体中出现了117个基因型,其中二倍体包含29.5个基因型,四倍体包含29个基因型,平均每个种群有29.25个克隆.物种水平上Simpson多样性指数(D)为0.992,基因型比率(PD)为0.700,表现出克隆多样性.二倍体克隆多样性(D=0.978,PD=0.846)略高于四倍体(D=0.974,PD=0.805).相关性表明环境因子与克隆多样性无显著相关.多基因型起源、兼性有性生殖和实生幼苗的更新可能是七筋姑不同倍型基因型丰富的来源.

Clintonia udensis is a member of Clintonia （Liliaceae）. As a perennial herbaceous plant, this specieshas two cytotypes which include diploid and tetraploid. The species can reproduce through root buds. In thisstudy, the clonal diversity and clonal structure of C. udensis was analyzed based on SSR molecular markers. Theresults showed that the diploid and tetraploid populations were all polyclonal populations, and that none monoclonal populations were found. There is a high clonal differentiation in two cytotypes. All the clonal structure of C.udensis was“Guerilla”. 152 C. udensis samples of four populations had 117 genotypes. The diploid had 29.9 genotypes, while the tetraploid had 29 genotypes. The average clone was 29.25 at the population level. Moreover,Simpson index （D） was 0.992 and genotype ratio （PD） was 0.700 at species level, which indicated high clonal diversity within C. udensis. The colnal diversity of diploid was slightly higher than that of tetraploid. There is nosignificant correlation between clonal diversity and environmental factors based on correlation analysis. In conclusion, multiple origins of genotypes, facultative sexual reproduction and updated seedlings should be the sources for maintaining rich genotypes within the C. udensis populations.