Genetic Variation of Thrips Populations Assessed by Amplified Fragment Length Polymorphism (Thysanoptera: Thripidae)

Abstract The levels of polymorphism and the genetic relationships of eight populations of two thrips species, Thrips tabaci Lindeman and Frankliniella occidentalis (Pergande), were studied using amplified fragment length polymorphism. We used two combinations of restriction enzymes (EcoR I/Mse I and EcoR I/Taq I) and studied six of these eight populations with each combination. The two species could be distinguished morphologically and are clearly distinguished one from the other by either enzyme combination. We found a few unique bands characterizing some of the populations within each species and a high level of polymorphism within each population. The relatively low polymorphism between populations compared with those between species, suggests that gene transfer between populations does occur. The high level of polymorphism within populations suggests a high level of heterozygosity and a significant level of sexual reproduction for both species.