Confirmation of Radish Isolate of Turnip mosaic virus in India through biological and serological evidences

Background and Objective: Oilseed brassica are one of the most exploited agricultural commodities in International trade with diversified use in human and animal consumption besides their potential use in producing green energy in the form of biofuels. Turnip mosaic virus is one of the limiting factors for declining oil content in brassica. The present studies were therefore conducted to confirm the presence of this important virus in brassica through biological and serological assays. Materials and Methods: A total of 518 samples collected from 84 locations spanning across 5 states and 1 union territory from symptomatic plants were collected and assayed in DAS-ELISA using Turnip mosaic virus (TuMV) specific polyclonal antiserum. Biological and serological host range of the virus isolate was established and different varieties/breeding lines of oilseed brassica were screened for developing a resistance panel against TuMV. Results: Turnip mosaic virus incidence ranged between 0.6-8.3% in oilseed brassica and 0.2-17.6% in crucifer vegetables. Turnip mosaic virus was recorded in very high concentration from radish as indicated by the optical density values. Mustard variety Tender Green was established as the best propagative host of Indian radish isolate of Turnip mosaic virus. Out of 32 varieties/breeding lines of oilseed brassica collected from different sources in India, 25 varieties/lines were found to be susceptible to Turnip mosaic virus under glasshouse conditions and DAS-ELISA further confirmed these findings. Conclusion: A radish isolate of Turnip mosaic virus has been identified on the basis of biological and serological assays and results obtained for screening of brassica germplasm against Turnip mosaic virus are expected to help in ascertaining the sources of resistance against this virus