RAPD-PCR analysis of molecular variability in the red rot pathogen (Colletotrichum falcatum) of sugarcane

摘要

Colletorichum falcatum is the causal organism of sugarcane red rot disease. For rapid identification and characterisation C. falcatum isolates, a Random Amplification of Polymorphic DNA (RAPD) technique has been developed and optimized. Decanucleotide primers e.g. GGTGCGGGAA, CCAGGTGCAC, GTGACATGCC and TCASGGAGGT were found to be useful in differentiating five Pathogenic variants, collected from Hayan. Of these five only four had been previously tested, on 13 different sugarcane varieties, for their pathogenicity. Five primers produced 73 DNA fragments from the genomic DNA of five different pathogenic variants/isolates of C. falcatum, of which 23 percent were polymorphic. DNA polymorphism in these isolates showed genetic variation in pathogenicitywithin a common agro-ecosystem. Total RAPD data derived from five primers and five isolates were used in the unweighted pair group method with arithmetic means analysis (UPGMA) to generate a tree of visual relatedness displaying genetic variations. By this method, the pathogenic potential of these isolates was separated into two distinct clusters.