Department of Plant Pathology, Faculty of Agriculture, AAU, Jorhat-785013, Assam, India.
Abstracts of the papers presented at the International Conference of Indian Virological Society on “Emerging and Re-emerging viral Diseases of the Tropics and Subtropics” at Indian Agricultural Research Institute, New Delhi, India, December 11–14, 2007.
A sudden outbreak of virus disease was noticed in capsicum and pulse crops viz., black gram, green gram and soybean during 2005 and 2006 in Assam. The diseased plant first exhibited brown necrotic areas in the leaves initially as streaks and finally necrosis on the stem. The key symptoms was necrosis of veins, midrib, petioles, stem and bud. In pulses, in addition to the above symptoms, yellowing, cupping and rolling of leaves were noticed. The plant affected at early growth stage were severely stunted withy reduced internodal length. High population of thrips were noticed on these crops and on peanut growth in nearby areas. Mechanical inoculation of the sap extracted from infected plants on young cowpea seedling showed chlorotic spots whereas, on Chenopodim amaranticolor and Datura stramonium showed necrotic spots, confirming the presence of virus in the infected sap. Based on these findings involvement of peanut bud necrosis virus (PBNV) in the disease etiology was suspected. Further studies on characterization of the virus is being carried out.
