National Symposium on Strategic Issues in Plant Pathological Research held at Department of Plant Pathology, CSK HP Krishi Vishvavidayalaya, Palampur on November 24–25, 2011
Chrysanthemum virus B (CVB) is a member of carlavirus group widespread throughout the chrysanthemum growing areas worldwide. Coat protein (CP) sequences from 31 geographical isolates of Chrysanthemum virus B (CVB) originating from varied agro-climatic zones of India were determined, analyzed and compared with other isolates from the world. The CP genes of the Indian CVB isolates were highly heterogeneous, sharing nucleotide sequence identities of 74–98%. Based on phylogenetic analyses, the isolates formed three groups potentially representing either two or three major CVB strain groups. The CP gene of isolates from Lucknow (Uttar Pradesh, UP), Chennai (Tamil Nadu, TN), Itanagar (Arunachal Pradesh, AR), Dehradun (Uttaranchal, UA) showed considerable heterogeneity from other isolates of CVB. On biological characterization these isolates also showed same heterogeneity. Four isolates representing different states and one isolate from other groups exhibiting similarity were completely sequenced thus constituted first complete sequence report of CVB. The variable regions from the five isolates were expressed as fusion protein in expression vector pGEX 2TK. Expressed proteins were purified and used as antigen for producing antisera. Cross reactivity studies of these antisera revealed the specificity of the antisera as antiserum raised against Uttaranchal, UA isolate (presently Uttarakhand) could not detect the isolate from Tamil Nadu isolate and vice-versa.
