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Molecular Plant Pathology

Genetic Diversity in Geminiviruses Causing Bean Golden Mosaic Disease: The Nucleotide Sequence of the Infectious Cloned DNA Components of a Brazilian Isolate of Bean Golden Mosaic Geminivirus. Robert L. Gilbertson, Department of Plant Pathology, University of Wisconsin, Madison 53706, Current address: Department of Plant Pathology, University of California, Davis 95616; Josias C. Faria(2), Paul Ahlquist(3), and Douglas P. Maxwell(4). (2)(4) Department of Plant Pathology, University of Wisconsin, Madison 53706; (2)Current address: EMBRAPA-Centro Nacional de Pesquisa Arroz-Feijão, Caixa Postal 179, Goiânia, Goiás, 74,000, Brazil; (3)Department of Plant Pathology and Institute for Molecular Virology, University of Wisconsin, Madison 53706. Phytopathology 83:709-715. Accepted for publication 25 February 1993. Copyright 1993 The American Phytopathological Society. DOI: 10.1094/Phyto-83-709.

The complete nucleotide (nt) sequence of a Brazilian isolate of bean golden mosaic geminivirus (BGMV-BZ) was determined from the infectious cloned DNA components. The genome of BGMV-BZ was divided between two DNA components, DNA-A (2,617 nt) and DNA-B (2,580 nt), which had little sequence identity except for a 181-nt common region present in both molecules. The genomic organization of BGMV-BZ was similar to that of other bipartite whitefly-transmitted geminiviruses, with six open reading frames (ORFs) encoding putative proteins >10 kDa, four on DNA-A (one in the viral [+] and three in the viral complementary sense [–]) and two on DNA-B (one in the viral and one in the viral complementary sense). All six BGMV-BZ ORFs were analogous to corresponding ORFs in other whitefly-transmitted geminiviruses. The homology between BGMV-BZ sequences and those of a BGMV isolate from Puerto Rico (PR) were relatively low. BGMV-BZ sequences were no more closely related to BGMV-PR than to other distinct geminiviruses from South America, such as tomato golden mosaic geminivirus. Pseudo-recombinants made by mixing the infectious cloned DNAs of BGMV-BZ and a BGMV isolate from Guatemala (GA), which was very similar to BGMV-PR, were not infectious. These results support previous observations of differences in sap-transmissibility and bean genotype reactions between BGMV isolates and indicate that at least two distinct types of BGMV exist, designated type I and II.