Mosaico do quiabeiro : etiologia, caracterização e diversidade

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

Okra mosaic disease was frequently observed in the 60s in Brazil, but its importance decreased after the use of the resistant cultivar Santa Cruz 47. It was believed that this disease was caused by a begomovirus, but the etiology was never confirmed. Several okra production fields were visited in central Brazil (Federal District and Goiás state) for evaluation of occurrence of begomovirus. Samples from plants showing chlorotic spots, mosaic symptoms or asymptomatic ones were collected and tested by using begomovirus universal primers. Among one hundred and ninety eight collected sintomatic or assintomatic plants, begomovirus were detected in three samples (samples #5157, 6319 and 6328). Total DNA was subjected to rolling circle amplification (RCA) and introduced into okra seedlings by biobalistcs. All three DNA bombarded samples gave rise to infected okra plants, confirmed by PCR, demonstrating that they were infectious to okra plants. DNA-A and DNA-B of three isolates were cloned (except for sample DNA-B of #6328) and their nucleotide sequences exhibited typical properties of new world bipartite begomoviruses. Clones of DNA-A and DNA-B from isolate #5157 were infectious to okra, Sida santaremnensis and some Solanaceae plants when inoculated by biolistics. According to the new taxonomic criteria for the Begomovirus genus, clones of the isolate #5157 belong to Sida micrantha mosaic virus species, while clones of the isolates #6319 and 6328 belong to a new species, tentatively named Okra mottle virus. This is the first report of a begomovirus infecting okra in Brazil. Until recently, the presence of a begomovirus in okra plants was not recognized, but in the present small-scale survey, two species were found, suggesting a considerable diversity of okra infecting begomoviroses species within Brazil.

ASSUNTO(S)

begomovírus quiabeiro mosaico caracterização molecular e biológica ciencias biologicas

ACESSO AO ARTIGO

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