Résumé
The complete infectious genome of an isolate of maize streak geminivirus from Reunion Island (MSV-R) was cloned and sequenced. Using an Agrobacterium tumefaciens Ti plasmid delivery system, the cloned 2.7kb circular DNA was shown to be infectious on maize. The agroinfected virus could be transmitted by Cicadulina mbila, the most common insect vector in Reunion. Based on nucleotide sequence analysis of the infectous clone, MSV-R differs from the three previously characterized African clones from Nigeria (MSV-N), Kenya (MSV-K), and South Africa (MSV-S). The open reading frames map found on MSV-R is the same as that of MSV-N, but differs from those of MSV-K and MSV-S on the complementary "-" strand. The comparison of the predicted peptide sequences of the proteins of potential proteins, shows that there are generally more differences between MSV-R and the African isolates, than there are among the African isolates. Consequences on pathogenicity and maize breeding for resistance to MSV in Reunion Island, are discussed. (Résumé d'auteur)