title: Genetic diversity and geographic distribution of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) genotypes associated with cassava in East Africa.
abstract: The genetic variability of whitefly (Bemisia tabaci) species, the vectors of cassava mosaic begomoviruses (CMBs) in cassava growing areas of Kenya, Tanzania, and Uganda, was investigated through comparison of partial sequences of the mitochondria cytochrome oxidase I (mtCOI) DNA in 2010/11. Two distinct species were obtained including sub-Saharan Africa 1 (SSA1), comprising of two sub-clades (I and II), and a South West Indian Ocean Islands (SWIO) species. Among the SSA1, sub-clade I sequences shared a similarity of 97.8-99.7% with the published Uganda 1 genotypes, and diverged by 0.3-2.2%. A pairwise comparison of SSA1 sub-clade II sequences revealed a similarity of 97.2-99.5% with reference southern Africa genotypes, and diverged by 0.5-2.8%. The SSA1 sub-clade I whiteflies were widely distributed in East Africa (EA). In comparison, the SSA1 sub-clade II whiteflies were detected for the first time in the EA region, and occurred predominantly in the coast regions of Kenya, southern and coast Tanzania. They occurred in low abundance in the Lake Victoria Basin of Tanzania and were widespread in all four regions in Uganda. The SWIO species had a sequence similarity of 97.2-97.7% with the published Reunion sequence and diverged by 2.3-2.8%. The SWIO whiteflies occurred in coast Kenya only. The sub-Saharan Africa 2 whitefly species (Ug2) that was associated with the severe CMD pandemic in Uganda was not detected in our study.
authors.affiliation: National Crops Resources Research Institute P.O. Box 7084, Kampala, Uganda ; School of Molecular and Cell Biology, University of the Witwatersrand P.O. Box 2050, BraamFontein, Johannesburg, South Africa.
authors.forename: Habibu
authors.initials: H
authors.lastname: Mugerwa
authors.forename: Marie E C
authors.initials: ME
authors.lastname: Rey
authors.forename: Titus
authors.initials: T
authors.lastname: Alicai
authors.forename: Elijah
authors.initials: E
authors.lastname: Ateka
authors.forename: Hellen
authors.initials: H
authors.lastname: Atuncha
authors.forename: Joseph
authors.initials: J
authors.lastname: Ndunguru
authors.forename: Peter
authors.initials: P
authors.lastname: Sseruwagi