濒危植物三棱栎遗传多样性的RAPD分析

用随机扩增多态DNA (RAPD)标记对 5个三棱栎 (Trigonobalanusdoichangensis)居群共 99个个体进行遗传多样性和居群遗传结构分析。 16个引物共检测到 15 7个位点 ,其中多态位点 83个 ,占 5 2 87%。物种水平Shannon多样性指数I =0 2 4 31,Nei基因多样度h =0 15 95 ,种内总遗传变异量Ht=0 16 0 0 ,居群内遗传变异量Hs =0 0 74 9,居群间变异量大于居群内变异量 ,表明三棱栎的遗传变异主要存在于居群之间。与同科植物相比 ,三棱栎遗传多样性较低 ,遗传分化系数Gst =0 5 32 0 ,说明居群间的遗传变异占 5 3 2 0 % ,居群间已出现强烈的遗传分化。当地人的强烈活动造成的生境破碎化和居群隔离 ,以及三棱栎演化过程中的地史变化对其种群发展的影响等 ,可能是造成其居群间强烈的遗传分化和较低遗传多样性的原因。基于本研究结果 ,提出了三棱栎遗传多样性的保护策略。

Analysis of Genetic Diversity of Trigonobalanus doichangensis (Fagaceae) by RAPD

The genetic diversity and population genetic structure of five populations with total of 99 Trigonobalanus doichangensis individuals were estimated with random amplified polymorphic DNA (RAPD) markers.One hundred and fifty-seven loci were amplified with 16 oligonucleotide primers,of which 83 loci (52.87%) were polymorphic.Shannon's information index (I) and Nei's gene diversity (h) were 0.2431 and 0.1595 respectively at the species level.Total genetic diversity (Ht) was 0.1600,and the genetic diversity within populations (Hs) was 0.0749.The genetic variation between different populations accounted for 53.20% of the total.This indicated that genetic variation existed mainly between populations rather than within populations.In comparison with other species from Fagaceae,the genetic diversity of T.doichangensis is lower and the gene flow among populations is very restricted.These may be attributed to the changes of environment during the species evolution,habitat destruction and excessively making use of the species resources by the people.Based on the research results,the conservation strategies of genetic diversity for the species were put forward.;RAPD ;Ge