NATURAL INFECTION OF GLYCINE MAX BY SEVEN VIRUSES BELONGING TO DIFFERENT GENERA IN INDIA
P. Sharma, S. Sharma, I. Gautam, V.K. Baranwal
Seventy seven soya bean accessions were screened at the Indian Agricultural Research Institute (IARI) experimental field during kharif season in the months of July to October to determine the prevalence and number of viruses affecting soya bean. Prominent symptoms included yellow mosaic, green mosaic/mottling and necrosis. ELISA, PCR and RT-PCR analysis showed mixed infection of seven viruses (Bean yellow mosaic virus, Blackgram mottle virus, Cowpea mild mottle virus, Cucumber mosaic virus, Groundnut bud necrosis virus, Mungbean yellow mosaic India virus and Tobacco streak virus) in different soya bean accessions. The predominant virus was Mungbean yellow mosaic India virus in 71 accessions followed by Tobacco streak virus infecting 60 accessions. None of the accessions was found to be infected with Tobacco ringspot virus or Soybean mosaic virus. Mixed infection with as many as five viruses (BMoV, CMV, GBNV, MYMIV, TSV) was observed in twelve accessions. Other accessions were infected with one to four viruses in different combination. Our study described the first report of Cucumber mosaic virus and Blackgram mottle virus infecting soya bean under natural conditions in India. Multiple viral infections potentially lead to increased symptom severity, therefore our findings have implications in the management of these viruses affecting soya bean.