Colonization of non-cassava plant species by cassava whiteflies (Bemisia tabaci) in Uganda
Sseruwagi, P., Maruthi, M.N., Colvin, J., Rey, M.E.C., Brown, J.K. and Legg, J.P. (2006) Colonization of non-cassava plant species by cassava whiteflies (Bemisia tabaci) in Uganda. Entomologia Experimentalis et Applicata, 119 (2). pp. 145-153. ISSN 0013-8703Full text not available from this repository.
Bemisia tabaci(Genn.) (Homoptera: Aleyrodidae) is the vector of cassava mosaic geminiviruses (CMGs), which are the main production constraint to cassava [Manihot esculenta Crantz (Euphorbiaceae)],both in Uganda and elsewhere in Africa. TwoB. tabaci genotype clusters, Ug1 and Ug2, differentiated at 8% nucleotide (nt) divergence within the mitochondrial cytochrome oxidase I (mtCOI) gene, have been shown to occur on cassava in Uganda. However, the role of alternative hosts in the ecology of cassavaB. tabaci genotypes and their possible involvement in the epidemiology of cassava mosaic disease (CMD) in Uganda remain unknown. In this study, we investigated the restriction of cassava B. tabaci genotypes to cassava and the colonization of alternative host species in select cassava-growing areas of the country in 2003 and 2004. Bemisia tabaci adults and 4th instar nymphs were collected from cassava and 11 other cultivated and uncultivated species occurring adjacent to the sampled cassava fields
Phylogenetic analysis of mtCOI sequences revealed that only a single genotype cluster, Ug1, was present on both cassava and non-cassava plant species sampled in this study. The Ug1 genotypes (n = 49) shared 97–99% nt identity with the previously described cassava-associated B. tabaci populations in southern Africa, and were ∼ 8% and ∼ 13% divergent from Ug2 and the ‘Ivory Coast cassava’ genotypes in Uganda and Ivory Coast, respectively. The Ug1 genotypes occurred (as adults) on all 12 source-plant species sampled. However, based on the presence of B. tabaci 4th instar nymphs, the Ug1 genotypes (n = 13) colonized cassava and five other non-cassava plant species: Manihot glaziovii, Jatropha gossypifolia, Euphorbia heterophylla,
Aspilia africana, and Abelmoschus esculentus, suggesting that cassava B. tabaci (Ug1 genotypes) are not restricted to cassava in Uganda. No Ug2-like genotypes were detected on any of the plant species sampled, including cassava, in this study. The identification of additional hosts for at least one genotype cluster, Ug1, known also to colonize cassava, and which was hitherto thought to be ‘cassava-restricted’ may have important epidemiological significance for the spread of CMGs in Uganda.
|Additional Information:|| Entomologia Experimentalis et Applicata is published on behalf of The Netherlands Entomological Society.|
|Uncontrolled Keywords:||Homoptera, Aleyrodidae, genetic diversity, mitochondrial cytochrome oxidase I (mtCOI)DNA, host races, ecology|
|Subjects:||S Agriculture > S Agriculture (General)|
S Agriculture > SB Plant culture
|School / Department / Research Groups:||Natural Resources Institute|
Natural Resources Institute > Agriculture, Health & Environment
|Last Modified:||04 Oct 2012 13:12|
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