摘要
Cymbidium goeringii is a diploid and non-rewarding,bumblebee-pollinated species,which is distribut-ed in China,Japan and Korea Peninsula.This species is now highly endangered due to the mass collection and forest clearance in China.In the present study,we investigated the distribution of genetic variation within and between eleven populations of Cymbidium goeringii in central China by using Inter-simple sequence repeats(ISSR)markers.Eleven primers produced a total of 127 clear and reproducible bands of which 112 were polymorphic.High genetic diversity was detected in Cymbidium goeringii for both population level(P=63.1%;He=0.1945)and species level(P=88.2%;He=0.2628).A higher level of genetic differentiation was detected among populations(G_(ST)=0.2440,F_(ST)=0.2207)with Nei’s GST analysis and analysis of molecular variance(AMOVA),and no correlation was found between geograph-ical and genetic distance.Genetic drift rather than gene flow played an important role in forming the present population structure of Cymbidium goeringii.Limited gene flow among populations and gene drift increase the extinction risk of local populations.Some conservation concerns are therefore dis-cussed together with possible strategies for implementing in situ and ex situ conservation.
基金
We are grateful to Drs Li Zuozhou,Chen Lei and Liu Yifei for their assistance and advice and Mrs Zhang Chunxia provided assistance in the field observation and collecting samples.The work was supported by the Natural Scientific Foundation of Hubei Province,China(2004ABA119)for Yang Bo.
