Diversity Among Isolates ofBean pod mottle virus

Abstract

Isolates of Bean pod mottle virus (BPMV), a member of the genus Comovirus, collected from soybean fields in Kentucky, Virginia, Arkansas, and Iowa were classified into two distinct subgroups, I and II, based on nucleic acid hybridization analysis using cloned cDNA probes to RNA-1 from BPMV strains K-G7 and K-Ha1. Slot blot hybridization analysis using cloned cDNA probes to RNA-2 from the same two strains (K-G7 and K-Ha1), however, revealed that some of the isolates, initially classified as belonging to subgroup I after analysis with RNA-1 probes, are in fact natural reassortants between the two strain subgroups. This was corroborated by nucleotide sequence analysis of full-length cDNA clones of both RNA-1 and RNA-2 from a putative reassortant strain (K-Ho1). These results indicate that BPMV strain diversity is more complex than initially anticipated, and that the use of cloned probes to both genomic RNAs during nucleic acid hybridization analysis is required to unravel the extent of such diversity. In a field plot experiment, BPMV isolates that belong to distinct strain subgroups induced symptoms that varied in severity and in the level of yield losses. In this regard, the reassortant strain K-Ho1 caused the most serious damage compared with four other BPMV isolates tested. Furthermore, the soybean alleles Rsv(1) and Rsv(4), known to confer resistance against Soybean mosaic virus, a member of the genus Potyvirus, did not provide any protection against BPMV. Additionally, we developed a reverse transcription-polymerase chain reaction procedure based on the sequence of a highly conserved region in the capsid polyprotein coding sequence that provides efficient and highly sensitive detection of all BPMV isolates tested, regardless of their strain classification.

Bean pod mottle virus: A Threat to U.S. Soybean Production

“…(63). Also, the virus genetic diversity identified to date (30) suggests the potential for corresponding host diversity based on what is known of other pathosystems. Screening of germ plasm will hopefully reveal these resistance genes.…”

“…A severe outbreak of BPMV in the north central and northern Great Plains states is currently causing serious concern to soybean growers and to the soybean industry in this region (30). BPMV is efficiently transmitted in nature, within and between soybean fields, by several species of leaf-feeding beetles.…”

“…The recent work of Gu et al (30) has revealed at least two genetically distinct BPMV subgroups, I and II. The two subgroups can be clearly distinguished by nucleic acid hybridization analysis (Fig.…”

“…6). Furthermore, Gu et al (30) isolated and characterized naturally occurring reassortants between the two subgroups. It is of interest that isolation of BPMV reassortants coincided with the recent increase of both virus incidence and BLB populations.…”

Plant Pathogen Forensics: Capabilities, Needs, and Recommendations

“…By a similar approach, most markers used with bacteria and viruses, and many fungi, are located on the same piece of DNA or RNA and thus may not be subject to frequent recombination. Exceptions are plasmids, horizontally transferred sequences, and genomes of multipartite viruses (69). Additionally, the degree of recombination varies among species.…”