Abstract: The genetic diversity of thirty-two Chinese populations of crofton weed Ageratina adenophora in different altitudes was analyzed with the inter-simple sequence repeat(ISSR) technique.The result indicated that genetic diversity of Chinese A.adenophora populations decreased along with the increased latitude(R²=(0.1311),p<0.05),whereas increased along with the longitude shift from west to east(R² =(0.1677),p<0.05).Genetic diversity of A.adenophora correlated highly with the annual mean temperature of its habitat(R² =(0.2731),p<0.01),whereas there was no significant correlation between its genetic diversity and the annual mean rainfall(R² =(0.0749),p>0.1).Cluster analysis grouped the Chinese crofton weed populations into two subgroups,which were corresponding with their geographical origins.The first subgroup included the populations located in the vegetation regions of tropic seasonal rain forest and rain forest,i.e,populations in southern Yunnan,Guangxi and southwestern Guizhou.The second subgroup included the populations located in the western semi-humid subregion of the subtropical evergreen broadleaf tree vegetation region,i.e,populations in middle to western Yunnan,Sichuan and area along the Yangtze River.The Mantel Z-statistic test showed that the genetic distance of A.adenophora populations was corresponded highly with their geographic distance(R² = 0.294,p>0.001),indicating that the geographic isolation is a main factor to block the gene flow of A.adenophora.

Key words: Ageratina adenophora, ISSR, Genetic diversity, Geographical location

CLC Number: 

• S54