1Plant Virus Lab., Division of Crop Protection, Central Reseach Institute for Jute and Allied Fibres, Barrackpore, Kolkata-700120.
2Plant Virology Unit, Division of Plant Pathology, Indian Agricultural Research Institute, New Delhi-110012.
Abstracts of Research Papers Presented during the National Symposium of Indian Virological Society at Unit of Plant Virology, Division of Plant Pathology, Indian Agricultural Research Institute, New Delhi-110 012, October 14–1.
The crop mesta (Kenaf and Roselle) is a potentially valuable industrial crop due to its fibre content, medicinal value and effective use in paper industry (Duke and Wain,1981). A severe yellow vein mosaic disease has been observed since last three years in mesta crop in eastern and southern India. The leaves of affected plant show yellowing of veins, which leads to complete yellowing of leaves at an advanced stage. The disease imparts heavy reduction in yield due to reduced chlorophyll content in leaves and retarded growth. Electron microscopy revealed the presence of geminate particles in the symptomatic leaves. The virus is effectively transmitted by whitefly (Bemisia tabaci) to both the species of mesta (Kenaf - HC583 and Roselle - HS4288), with an acquisition and inoculation access period of 24 hr each. The typical symptoms appeared after a minimum incubation perriod of 9 days under glasshouse condition. The disease is also transmitted by cleft grafting. However, seeds and sap from infected plants could not transmit the disease. Primers specific to β-DNA (Briddon et al., 2003) gave an expected amplicon of 1.3 kb size from infected leaves, indicating the possible association of satellite β-DNA with the disease. However, no amplification was observed with DNA A specific primers of Cotton leaf curl virus, Tomato leaf curl virus and Mungbean yellow mosaic virus, and thus indicated that the causal virus may have difference in DNA A component from all these viruses. The Southern blot analysis and nucleic acid spot hybridization test using α-32P radiolabelled probes to Cotton leaf curl Rajasthan virus DNA A (Accession No. NC003199) and β-DNA associated with cotton leaf curl virus (CLCuDb0IInd, Accession No.AY083590) gave a positive hybridization signal and thus indicated the involvement of a Begomovirus related to Cotton leaf curl Rajasthan virus with the disease. Hence, this constitutes the first record of a Begomovirus, related to Cotton leaf curl Rajasthan virus containing a satellite β-DNA, associated with yellow vein mosaic disease of mesta in India.
