Genetic diversity of Alnus nepalensis in Yunnan revealed by RAPD-PCR

Alnus nepalensis is the oldest species of Betulaceae,mainly distributed in Yunnan Province,which can fix nitrogen.The objective is to study its genetic diversity and assess its resources.In Yunnan Province 58 naturally occurring samples of A.nepalensis were collected from Laifeng,Gaoligong,Jizu,Cang,and Wuliang Mountains.The genomic DNA of A.nepalensis was as extracted by the cetyltrimethylammonium bromide(CTAB) method,and their DNA polymorphism was analyzed by random amplification of polymorphic DNA(RAPD)-polymerase chain reaction(PCR) with 3 optimum primers.A total of 85 DNA bands were amplified,and a DNA molecular UPGMA(unweighted pair group method using arithmetic averages) dendrogram was established.Also,for the samples,Nei's gene diversity and Shannon's information index were computed by POPGENE software Numerical Taxonomy SYStem(NTSYS) software.Results indicated that 64 of the 85 DNA bands(75.3%) were polymorphic,and with the dendrogram A.nepalensis samples were placed into 6 groups with a standard similarity coefficient of 0.68.A.nepalensis possessed abundant genetic diversity with the highest diversity found in the Jizu Mountains.In the Wuliang Mountains genetic diversity of A.nepalensis was richer along the southern slope than the northern.Also,a close relationship between the genetic structure of A.nepalensis and the environment was shown with genetic diversity.