RESOLUTION OF POPULATIONS OF THE MEDITERRANEAN FRUIT-FLY AT THE DNA LEVEL USING RANDOM PRIMERS FOR THE POLYMERASE CHAIN-REACTION

We have used the polymerase chain reaction (PCR) and the random amplif ied polymorphic DNA (RAPD) method to identify DNA polymorphisms that c an be used as genetic markers to characterize populations of the Medit erranean fruit fly, Ceratitis capirata. In this study, RAPD markers ha ve been used to resolve genetic variability between populations of thi s major agricultural pest species. The populations analyzed represent either laboratory stocks or wild collections originating from differen t geographic localities. Using the same set of individual flies from e ach of several populations, we show that the use of different primers in the RAPD method permits detection of different levels of population differentiation. We show results from RAPD primers (e.g., primer 14) that identify regions of the genome (through PCR amplification) that a re essentially monomorphic in all flies originating from a particular geographic locality. We also show RAPD primers (e.g., primer 67) that identify what appear to be highly variable regions of the genome. We h ave used primers of this type to produce genetic markers that can dist inguish even between laboratory versus wild populations as well as sub populations of flies from more broadly defined geographic localities, such as within the Hawaiian islands. These results show that the RAPD method is a broadly applicable, high resolution method for documenting genetic variability within and between populations of insect pest spe cies.