Molecular characterization of whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae) populations infesting cassava.
Bemisia tabaci (Gennadius) populations, collected from cassava and other plants in major cassava-cultivation areas of Sub-saharan Africa and from elsewhere around the world, were studied to determine their biotype status and genetic variation. Random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) markers were used to examine the genetic structure of the populations. The dendogram obtained using the neighbour joining method (NJ) split the cassava-associated populations from the non-cassava types with a 100% bootstrap probability. Analysis of molecular variance (AMOVA) of the RAPD fragments revealed that 63.2% of the total variation was attributable to differences among populations, while the differences among groups (host) and within populations accounted for 27.1 and 9.8% respectively. Analysis of the internally transcribed spacer region I (ITS 1) of the ribosomal DNA confirmed that the cassava populations of B. tabaci populations were distinct from non-cassava populations. Experiments to establish whitefly populations on various host plants revealed that cassava-associated populations were restricted to cassava only, whereas B. tabaci from other hosts were polyphagous but did not colonize cassava. Hence, populations of B. tabaci from cassava in Africa represent a distinct group.
Abdullahi
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Department of Crop Protection and Environmental Biology, University of Ibadan, Nigeria.
Winter
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Atiri
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GI
Thottappilly
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D000818:Animals; D021903:DNA, Ribosomal Spacer / Q000032:analysis; D014644:Genetic Variation; D006430:Hemiptera / Q000145:classification* / Q000235:genetics*; D002365:Manihot / Q000469:parasitology*; D010802:Phylogeny; D019105:Random Amplified Polymorphic DNA Technique / Q000662:veterinary; D013045:Species Specificity
D021903:DNA, Ribosomal Spacer