金钱槭属植物的遗传多样性与保护策略

Genetic Diversity and Implications for Conservation of Dipteronia Olive.

金钱槭属包括2个种:金钱槭(Dipteronia sinensis Oliv.)和云南金钱槭(Dipteronia dyeriana Henry),均为珍稀濒危植物,主要分布于中国的中部和南部。该研究应用18种随机扩增多态性DNA(RAPD)引物、8对扩增片段长度多态性(AFLP)引物和10种多态性叶绿体微卫星基因(cpSSR)引物,获得金钱槭和云南金钱槭的遗传多样性与种群结构的相关信息。结果表明,在物种水平上,由RAPD(金钱槭:H=0.386 4,Hsh=0.556 3;云南金钱槭:H=0.304 7,Hsh=0.445 0)和AFLP(金钱槭:H=0.331 9,Hsh=0.488 0;云南金钱槭:H=0.304 7,Hsh=0.4450)2个核标记的遗传多样性具有可比性,而cpSSR标记(金钱槭He=0.603 2,云南金钱槭He=0.671 1)的遗传多样性高于AFLP和RAPD标记的遗传多样性,遗传分化系数(GST)也显示出相似的结果,由此揭示2个种均拥有相对较高的遗传多样性和遗传分化。研究认为,人类活动破坏植物栖息地是造成2种物种处于濒危状态的主要原因;从长远来看,保护2种金钱槭属植物的主要策略是保护植物栖息地,同时应加强扩大种群规模以维持现有遗传变异水平。

The genus Dipteronia Oliv. endemic to central and southern China consists of two species, D. sinensis Oliv. and D. dyeriana Henry,both of them are rare and endangered. In this study,a combination of 18 random amplified polymorphic DNA（RAPD） markers, 8 pair of amplified-fragment length polymorphism（AFLP） primers and 10 polyrnorphic chloroplast microsatellite loci（cpSSR） were used to access thegenetic diversity and population structure of species D. sinensis and D. dyeriana. At the species level, the genetic diversity estimated by the two nuclear markers RAPD（D. sinensis：H=O. 386 4, Hsh 0. 556 3 and D. dyeriana：H=O. 304 7,Hsh=0. 445 0） and AFLP（D. sinensis：H=O. 331 9,Hsh=0. 488 0 and D. dyeriana ： H= 0. 304 7, Hsh = 0. 445 0） were comparable, while that of cpSSR（He = 0. 603 2 of D. sinensis and Ho =0. 671 1 of D. dyeriana） were much higher than that of both AFLP and RAPD,and the gene differentia- tion coefficient（Gsw） displayed a similar trend. The resulting values indicated that the three marker types estimated a relative high genetic diversity and genetic differentiation within both species. For the implica-tion of conservation, we believe that the habitat destruction by human activities is among the key factors responsible for both species＇ endangered status. Therefore,in the long term,the strategy for conservation of the two Dipteronia species is the protection of its habitat. In addition, increasing small population size to maintain existing levels of genetic variation should be taken into consideration.