Brown, J.K., Department of Plant Sciences, University of Arizona, Tucson, AZ 85721, United States
Lambert, G.M., Department of Plant Sciences, University of Arizona, Tucson, AZ 85721, United States
Ghanim, M., Department of Entomology, Agricultural Research Organization, Bet Dagan, Israel
Czosnek, H., Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, Faculty of Agriculture, Hebrew University of Jerusalem, Rehovot 76100, Israel
Galbraith, D.W., Department of Plant Sciences, University of Arizona, Tucson, AZ 85721, United States

The nuclear DNA content of the whitefly Bemisia tabaci (Gennnadius) was estimated using flow cytometry. Male and female nuclei were stained with propidium iodide and their DNA content was estimated using chicken red blood cells and Arabidopsis thaliana L. (Brassicaceae) as external standards. The estimated nuclear DNA content of male and female B. tabaci was 1.04 and 2.06 pg, respectively. These results corroborated previous reports based on chromosome counting, which showed that B. tabaci males are haploid and females are diploid. Conversion between DNA content and genome size (1 pg DNA = 980 Mbp) indicate that the haploid genome size of B. tabaci is 1020 Mbp, which is approximately five times the size of the genome of the fruitfly Drosophila melanogaster Meigen. These results provide an important baseline that will facilitate genomics-based research for the B. tabaci complex. © CAB International, 2005.