Analysis of genetic differentiation in different populations of Adoxophyes orana based on AFLP

The AFLP technique was used to analyze genetic differentiation among 4 populations of Adoxophyes orana( Fischer von Rosslerstamm). Three pairs of primers,and 224 DNA fragments were generated,195 of which were polymorphic. Genetic diversity analysis of the populations showed a high level of genetic variation among them with Shannon's genetic diversity index ranging from 0. 2137 to 0. 2383 and Nei genetic diversity index ranged from 0. 1425 to 0. 1578. Remarkable genetic differentiation indicated by genetic differentiation coefficient( Gst) and gene flow( Nm) was detected between northern and southern populations. There was relatively strong gene flow and low genetic differentiation among the three northern populations. AMOVA analysis indicated that a high percentage of the total genetic variance( 66. 81%) was explained by the variation among populations. UPGMA cluster analysis indicated that genetic distances were closer among the Shandong,Beijing and Shanxi populations,and thus these three populations should be grouped into one clade whereas the Fujian population should be placed in another clade. The results suggest that genetic distance might be correlated with host similarity rather than the geographic distance between populations.