GENETIC DIVERSITY OF FIVE GEOGRAPHICAL POPULATIONS IN SOLEN GRANDIS BY AFLP MARKERS

The AFLP (Amplified fragment length polymorphism) technology was used to estimate the genetic diversity of Solen grandis from several coastal sites of China. 141 natural individuals from 5 geographical populations of S. grandis located at Dandong (DD), Yantai (YT), Laizhou (LZ), Rizhao (RZ), and Nantong (NT) were analyzed using 7 pairs of AFLP primers. A total of 403 reproducible loci were generated, most of which varied from 100bp to 700bp. There was little different in the genetic diversity of DD, YT, LZ and NT, whereas the ratio of polymorphic loci of RZ was relatively higher than the other four populations. Combined with the Shannon’s index and Nei's genetic diversity index, RZ had the highest genetic diversity and NT had the lowest. AMOⅤA analysis showed that the genetic differentiation coefficient of S. grandis populations (Φst ) was 0.2250 (P0.001) and there was 77.5% genetic differentiation within the populations and 22.5% among the populations. These results indicated the genetic diversity detected was mainly caused by individual differences within a population, but there was somewhat gene flow between the populations.