Species diversity, phylogeny and evidence of recombination in begomoviruses associated with yellow mosaic disease of moth bean (Vigna aconitifolia) in South India

Abstract

Polymerase chain reaction assays of eight yellow mosaic disease (YMD) affected moth bean samples using specific primers indicated the presence of Mungbean yellow mosaic virus (MYMV), Mungbean yellow mosaic India virus (MYMIV) and Horsegram yellow mosaic virus (HgYMV) in two samples (Mo1 and Mo5) and two of these three viruses in remaining six samples. Sequence data analysis of Mo1 and Mo2 revealed the involvement of multiple DNA‐A and DNA‐B molecules in both samples. Further analysis of DNA‐A and DNA‐B molecules confirmed the presence of three viruses viz., MYMIV, MYMV and HgYMV, in Mo1 and of two MYMV and HgYMV in Mo2 samples. Analysis of common region (CR) sequences of components (DNA‐A and DNA‐B) of each virus indicated >85% nucleotide identity confirming them to be cognate and species integrity. The recombination analysis revealed the presence of a total of six putative recombination events in the viruses under study. In a phylogenetic analysis of DNA‐A sequences of the viruses under study with bipartite legume‐infecting begomoviruses and some selected old and new world begomoviruses, MYMIV, MYMV and HgYMV grouped with respective virus species. Similar grouping and clustering were found in the DNA‐B sequences also. The present study reports infection by HgYMV in moth bean and the association of three viruses (MYMIV, MYMV and HgYMV) with moth bean yellow mosaic disease for the first time. The presence of mixed infection of begomoviruses provides opportunities for the exchange of DNA between the species which may lead to the development of new strain/virus species.

Identification of potential sources of mungbean yellow mosaic India virus resistance in black gram (Vigna mungo) and expression of antioxidants and R‐genes modulating resistance response in cultivated and its two wild relatives

“…The three different viruses are involved in causing YMD in different vigna crops (Naimuddin et al, 2016). Whereas, a recent report indicated the mix infection causing YMD in Vigna stipulacea (Akram et al, 2021). The viral genome sequence identity exhibited the close relationship between YMD‐causing viruses, which comprised of mainly (i) mungbean yellow mosaic Indian virus ( MYMIV ), (ii) mungbean yellow mosaic virus ( MYMV ), (iii) and horsegram yellow mosaic virus ( HgYMV ); in which MYMIV and MYMV are reported as casual organism for YMD in black gram (Naimuddin et al, 2016).…”