Cross infectivity analysis of Yellow Mosaic Virus Disease in Blackgram, Greengram and Redgram

Studies on virus vector relationship between YMV (Yellow Mosaic Virus) and whitefly revealed that the per cent transmission (PT) by whitefly collected in blackgram (VBN 8) from the village Sembanarkovil of Mayiladuthurai district of Tamil Nadu, India, recorded a PT value of 100 when compared to the other villages. The variety VBN Gg 3 collected from the village Mathampatti of Coimbatore district of Tamil Nadu, India, recorded a PT value of 62.50. The MYMV from the blackgram, infected the blackgram plants with a score of grade 9 and infection percentage of 58%. Severe yellowing of leaves in over 75% of foliage, stunting of plants and absence of pod formation was observed. The MYMV from the greengram, infected the greengram plants with an infection score of grade 8 and an infection percentage of 60%. The plants showed severe yellowing of leaves in over 75% of foliage, stunting of plants with no pod formation. Cross infectivity of YMV disease from blackgram to greengram and from greengram to blackgram recorded was 60% and 2.5%, respectively. Whereas, no transmission of YMV from blackgram and greengram to redgram was observed and therefore recorded 0% infectivity.