Geographical distribution and molecular characterization of begomovirus infecting soybean [Glycine max (L.) merr.] in northern hills and north western plains of India

Yellow mosaic disease (YMD) is one of the most severe and widespread constraint for the cultivation of soybean. Given that no comprehensive data on the status of soybean yellow mosaic disease in Northern Hills and North Western Plains of India is present, a detailed investigation was undertaken for three years to study the prevalence of the disease in the region and to characterize the pathogen.

Towards Kharif end, a three year (2018-2020) farmer field survey (76 villages) was carried out to assess the YMD distribution in the major soybean growing areas Northern Hills and North Western Plains of India. The variability of yellow mosaic virus associated with YMD of soybean was studied based on molecular characterization of partial DNA-A coat protein gene and DNA-B movement protein with subsequent nucleotide sequencing and phylogenetic tree construction.

The results revealed that YMD is prevalent in the plains, whereas the disease was undetectable in the Hills. In the plains, the mean disease incidence ranged from 25.40% in 2019 to 16.78% in 2020. Moreover, disease incidence (r = -0.748) had negative and significant (p<0.0001) correlation with altitude. The phylogenetic studies revealed that the virus inciting the yellow mosaic in soybean in Tarai region had closest relationship with Mungbean yellow mosaic India virus (MYMIV). It shared more than 96 per cent sequence identity with other MYMIV isolates reported earlier within the country and abroad and hence, was designated as an isolate of MYMIV.