Genetic variability of Bemisia tabaci in the Mediterranean and Sahel Regions

The whitefly Bemisia tabaci is regarded as a complex species because of its high genetic variability, and at least 20 haplotypes/biotypes with varying degrees of biological characterization are currently recognized within the species. In the Mediterranean Basin and the Sahel Region the whitefly is widespread on a high number of wild and cultivated plant species. We analysed the genetic variability of B. tabaci by means of sequencing and restriction analyses of the mtCOI sequence. The results show the presence of five different biotypes in the Mediterranean Basin, B, Q, M, S, and T and of two haplotypes/biotypes in the Sahel Region, J and Sub-Saharan VI. According to their sequence analyses B, Q, and J belong to the Mediterranean/North African clade, S and Sub-Saharan VI to the African clade, while T falls within the Southeast/Fareast Asian clade. A diagnostic PCR-RFLP of mtCOI can be applied to identify most of these genetic variants.