RAPD characterization of Corticium salmonicolor causing pink disease of trees

Abstract

Corticium salmonicolor, fungal pathogen causing pink disease has a wide host range affecting major economically important tree species such as mango, orange, tea, coffee, eucalypts, acacias, rubber and teak. Because of its world-wide distribution, continued attention is paid towards host range, biology and genetic diversity of the pathogen. The present study was undertaken to determine the degree of genetic variation in five random isolates of C. salmonicolor. RAPD analysis was carried out using 10 selected primers; 102 RAPD loci and 50 per cent polymorphism were observed among the loci. Genetic distance coefficients between the isolates varied from 0.124 to 0.187. Mantel test did not reveal significant correlation between geographic distance of pathogen origin and genetic distance. RAPD genotype clustering was not in agreement with geographic isolation. The increased incidence of pink disease on tree crops and low genetic diversity of pathogens reveals the importance of further studies for a better understanding of genetic variability of this fungal pathogen in order to develop appropriate disease control measures.