濒危植物毛瓣金花茶遗传多样性的ISSR分析

Genetic Diversity Analysis of Endangered Plant Camellia pubipetala Detected by ISSR

采用ISSR分子标记对毛瓣金花茶6个自然居群的遗传多样性进行了分析。利用11个引物对150个个体进行了扩增,共扩增出92条条带,其中多态性条带74条。毛瓣金花茶在物种水平和居群水平都表现出相对较高的遗传多样性,在物种水平上,多态位点百分率(PPB)为80.43%,Nei’s基因多样性指数(h)为0.245 1,Shannon多样性指数(I)为0.377 6;在居群水平上,PPB为58.70%~66.30%,h为0.199 7~0.229 3,I为0.300 9~0.343 8。Nei’s遗传多样性分析和AMOVA分析表明,毛瓣金花茶的遗传变异主要存在于居群内,居群间的遗传分化程度较低(Gst=0.126 6,Φst=11.37%),基因流(Nm)为3.448 0。Mantel检测表明,居群间的遗传距离和地理距离之间存在显著的相关关系(r=0.755 1,P<0.05)。研究认为,毛瓣金花茶较高的遗传多样性和较低的遗传分化可能与其异交型繁育系统和鸟类传粉有关。

ISSR markers were used to analyze the genetic diversity and genetic structure of 6 natural populations of Camellia pubipetala. Eleven primers were used to amplify DNA samples from 150 individuals,and a total of 92 loci were detected. The genetic diversity of C. pubipetala is relatively high both at the species level and population level. At the species level,the percentage of polymorphic bands （PPB） is 80.43%, Nei＇s gene diversity （h） is 0. 245 1,Shannon information index （I） is 0. 377 6. At the population level, PPB range from 58.70%~66.30%,h range from 0. 199 7--0. 229 3,I range from 0. 300 9~0. 343 8. A low level of genetic differentiation among populations was detected based on Nei^s genetic diversity analy- sis （Gs~=0. 126 6） and analysis of molecular variance （q^t=ll. 37%）. Gene flow （Nm） among the popula- tions is high （3. 448 0）. A mantel test showed there was a significantly correlation between genetic and geographic distance among the populations studied （r=0. 755 1 ,P^0.05）. Relatively high genetic diversity within the population and the low population differentiation of C. pubipetala might be related to its outcrossing mating system and bird pollination.