闽楠天然种群遗传多样性的RAPD分析

RAPD analysis on genetic diversity in eight natural populations of Phoebe bournei from Fujian and Jiangxi Province,China

利用RAPD分子标记分析了闽楠主要分布区江西和福建两省的8个天然种群的遗传多样性和种群遗传分化。应用12条引物从160个植株中共检测到135个位点,其中多态位点134个。RAPD数据经Lynch-Milligan矫正后利用POPGENE软件计算出种群间遗传分化系数GST为0.373;利用Shannon多样性表型指数估算出46.4%的变异存在于种群间;分子方差分析(AMOVA)亦显示种群间变异占43.3%(P<0.001)。尽管遗传变异主要存在于种群内,但闽楠种群间亦存在强烈的遗传分化,这可能与闽楠种群生境片断化、地理隔离等有关。根据闽楠的遗传变异特点,建议尽可能多地保护闽楠天然种群,对遗传多样性较高的福建西芹、浦城、明溪等种群应予以重点保护,同时收集各地闽楠遗传资源进行迁地保护,并通过种群扩繁以及合理回归自然等方式扩大种群规模、增强种群间的基因流,以维持其遗传多样性水平。

Random amplified polymorphic DNA（RAPD） markers were used to estimate the genetic diversity and population genetic differentiation in eight natural populations of Phoebe bournei from Jiangxi and Fujian provinces,China.In the 160 individuals,12 random primers generated a total of 135 reproducible and discernible loci,among which 134 were polymorphic.37.3% of genetic variance was observed among populations,as revealed by POPGENE software after Lynch ＆ Milligan′s（1994） correction.And according to the analysis of Shannon′ index of phenotypic diversity,46.4% of genetic variation resided among populations.This was congruent with estimation of genetic variation by the analysis of molecular variance（AMOVA）,which revealed that 43.3% of the total genetic diversity（P〈0.001） was found among populations.Although its genetic variation mainly existed within populations,strong genetic differentiation occurred among populations perhaps mainly due to habitat fragmentation and isolation by distance,these were also the main causes for its endangered situation.Based on the results presented in this study,we recommended that attentions should be paid to protect as more populations as possible of this species,especially those populations with high genetic diversity in Xiqin,Pucheng and Mingxi,Fujian Province,and to collect genetic resources in the whole distribution areas for ex-situ conservation.It is also essential to enlarge its population scale by breeding and increase gene flow carefully by proper return-to-nature methods, so as to maintain its high level of genetic diversity.