Molecular characterization of a new bipartite begomovirus that infects okra plants in guerrero, Mexico

Abstract

In Mexico, okra (Abelmoschus esculentus L.) is grown mainly for export, but its production is affected by various pests and diseases. Plants with mosaic and chlorotic mottling symptoms were collected in Iguala, Mexico. The transmission tests revealed that the disease was not transmitted neither by seed nor by mechanical means. However, it was transmitted by grafting and by insect vectors. The entire nucleotide sequences of the DNA-A component of three isolates were obtained by PCR and sequencing; all of them were bipartite begomoviruses. The composition of the DNA-A component consists of five open reading frames (ORFs), one in the sense orientation (AV1) and four in antisense orientation (AC1, AC2, AC3 and AC4), in addition to the common region (CR). Sequence comparison and demarcation analyses revealed the presence of a new strain of Okra yellow mosaic Mexico virus—[Mexico:Isolate 13–14:2010], and a new species not previously reported and tentatively named Okra mottle Mexico virus, OMoMV—[Mexico:2005]. The phylogenetic analysis placed the new species in the clade that contains Chino del tomate virus. Recombination analyses suggest that this virus has a putative recombinant event of 93 bases, which may have originated across the exchange of genomic segments in the ORF AV1 + CR region from Chino del tomate virus, Okra yellow mosaic Mexico virus and Corchorus yellow spot virus.