Plant Virology Unit, Division of Plant Pathology, Indian Agricultural Research Institute, New Delhi-110012, 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.
Whitefly transmitted geminiviruses belonging to the genus Begomovirus of the family Geminiviridae are a major problem for many crop production system in India. The important crops affected are cassava, cotton, grain legumes, tomato, cucurbits and okra. Recently new host species which were not known to be infected by begomoviruses, are affected like potato and crucifers. The genotypes of hosts like cotton, okra and tomato, which were resistant to begomoviruses have now succumbed to their infection. Perusal of data leading to this situation revealed frequent occurrence of following events: (1) Multiplicity of monopartite and bipartite begomoviruses, with diverse genomic components (DNA A alone, A+ß, A+B, A+B+ß) affecting the same crop. (2) Association of different DNA β with one DNAA component depending on the geographical region from which isolated (3) Component capturing, common region exchange and recombination between co-infecting begomoviruses and (4) whitefly population build-up. Occurrence of above events in different host/virus system in India in the last five years and their consequences will be discussed.
