Studies On Taxonomy And Genetic Diversity Of Cultured Oysters In Coastal Sea Of Fujian

In this study, we used multiplex species-specific PCR to identify main cultivated oyster species in coastal sea of Fujian. Study materials were sampled from major oyster cultivated area using two seedling collecting ways that were collecting seedling from sea area and artificial breeding. Shell characteristic indexes of the cultivated populations were measured and the genetic diversity of the samples was analyzed using amplified fragment length polymorphism(AFLP). The results are as followed:Part one:we used multiplex species-specific PCR to identify oyster species of10cultivated population in coastal sea of Fujian and measured their shell characteristic indexes. This study randomly analyzed180individuals and120individuals from the six sea area seedling cultivated populations and the four artificial rearing seedling cultivated populations, respectively. The results showed that17Crassostrea sikamea individuals were found from two sea area seedling cultivated populations,and Crassostrea angulata were found in other eight sea area seedling cultivated populations and all the artificial rearing seedling cultivated populations. There was no significant difference between the two classes oyster cultivated populations (p=0.000) and no difference between Crassostrea sikamea and Crassostrea angulata from the same cultivated population (p>0.05).Part two:We used AFLP to analyze the genetic diversity of eight oyster cultivated populations.331fragments were detected using5primer combinations, of which98were shared by eight populations and233were polymorphic. Number of alleles, Effective number of alleles, Shannon’s information index and Expected heterozygosity of the eight populations were1.5581、1.3834、0.3339and0.2239, respectively. The genetic diversity index of sea area seedling cultivated populations was higher than that of artificial rearing seedling cultivated populations. In the sea area seedling cultivated populations, SSZ was the one with the highest genetic diversity index and PT was the one with the lowest genetic diversity index. And as to the artificial rearing seedling cultivated populations, SSR was the one with the highest genetic diversity index and ND was the one with the lowest genetic diversity index. The Nei’s genetic distance and the genetic similarity of eight oyster cultivated populations indicated that there was little genetic variation in sea area seedling cultivated populations and more obvious genetic variation in artificial rearing seedling cultivated populations and significant difference between the two classes of oyster cultivated populations. AMOVA analysis showed that the genetic variation was mainly within population. The result of UPGMA and NJ clustering analysis coincided with PC A, which indicated that the two classes of oyster cultivated populations were both divided into two groups.