Abstract

The Whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) causes damages to crops by feeding and/or transmitting various plant pathogenic viruses. Morphologically indistinguishable populations of B. tabaci can exhibit variable molecular features and biological behavior. The objective of this work was to present the molecular profile and genetic variability of B. tabaci collected from several crops and localities in Brazil. The molecular identification of 100 whiteflies samples collected from these crops and localities in Brazil revealed 14% of non B biotype of B. tabaci. About the biotypes of B. tabaci, 2% indigenous Brazilian whitefly was found, 1% A biotype, 2% Q biotype, 1% African cassava and 80% B biotype. The dendrogram obtained by molecular markers showed that biotype A of B. tabaci from the United States differed from the other biotypes as it showed around 8% of genetic similarity. For the remaining populations previously identified as biotype B, separation was observed among them based on location and crop of collection. The B. tabaci native Brazilian biotype did not form a separate grouping from the B biotype. This information may serve as a basis for studies aiming to identify which factors influence the population distribution in a given area.

Key words: Genetic markers, whitefly, oligonucleotides, b biotype, host plants association.