Detection of Carnation ringspot and carnation vein mottle viruses in carnation cultivars in India

A survey of sixty one carnation cultivars growing in the state of Himachal Pradesh, India showing varied symptoms on the leaves and flowers, were screened through bioassay and ELISA which revealed the widespread presence of Carnation vein mottle virus (CVMoV) and Carnation ringspot virus (CRSV). Out of sixty-one cultivars tested forty-seven were found infected with CRSV while thirty-four were found infected with CVMV using ELISA. Routine diagnostic techniques like RTPCR further confirmed infected samples for presence of these viruses. Besides RTPCR, immunocapture RT-PCR (IC-RT-PCR) was used for specific detection of CVMoV. The amplified DNA fragment of similar to 335 by was obtained by RT-PCR and IC-RT-PCR, using potyvirus group specific degenerate primers. Electron Microscopy (EM) of the purified virus particles was also performed for morphological studies of virus which revealed the presence of flexuous virus particles measuring e.750 x 11 nm. Sensitive detection by IC-RT-PCR will be helpful in production and propagation of plant material with minimum infection. For CRSV, some cultivars found negative by ELISA, when tested by RT-PCR were found positive (primers designed during the present study were used for amplifying the genes present on RNA1 and RNA2 of CRSV). These findings confirmed that CRSV is still widespread in India and thus emphasizes the need for indexing and production of virus-free quality planting materials.