Low genetic variability in Bemisia tabaci MEAM1 populations within farmscapes of Georgia, USA

Sweetpotato whitefly, Bemisia tabaci Gennadius, is a
serious pest of many agricultural crops worldwide. Numerous studies have
examined the genetic structure of whitefly populations separated by
geographical barriers; however, very few have assessed the population
structure of B. tabaci at a farmscape level. A farmscape
in this study is defined as heterogenous habitat with crop and non-crop
areas spanning about 8 square kilometers. To assess the roles of
farmscapes as drivers of B. tabaci genetic variations,
thirty-five populations of the sweetpotato whitefly were collected from
crop and non-crop plant species from fifteen farmscapes. Using
mitochondrial COI gene sequences (mtCOI) and six nuclear microsatellite
markers, the genetic diversity and genetic differentiation among
collected B. tabaci MEAM1 populations were examined.
Haplotype analysis using mtCOI sequences revealed the presence of a
single B. tabaci MEAM1 haplotype across farmscapes of
Georgia. Results from microsatellite markers further showed no significant
genetic structuring among populations that corresponded to plant species
or farmscapes from which they were collected. Annual whitefly population
explosions and subsequent dispersal might have facilitated the presence of
a single panmictic B. tabaci population over all sampled
farmscapes in this region.