Molecular characterization of Mangnoporthe grisea isolated from buffel grass (Cenchrus ciliaris) in Tamil Nadu, India

The fungus Magnaporthe grisea was isolated from the infected plants with blast-like lesions. The isolates were confirmed by PCR using primers specific for 28S rDNA of M. grisea. The Internal Transcribed Spacer (ITS) region of rDNA, which included ITS regions 1 and 2, 5.8S rRNA genes was amplified with primers ITS1 and ITS4. The PCR amplified product was approximately 550 bp in size. Analysis of nucleotide sequence of ITS regions of isolate CBECCI using NCBI-BLAST search showed 99% similarity with the sequence of Pyricularia sp. NI981 isolate from C. ciliaris. Cluster analysis using unweighted pair-group method with arithmetic average (UPGMA) clearly separated the M. grisea isolates into two groups. The isolate CBECC1, isolated from C. ciliaris clustered into a separate group (Group I) and all the remianing M. grisea isolates from GenBank database were clustered together in Group II confirming the genetic diversity among the M. grisea isolates. Sequences of the partial β-tubulin gene of M. grisea isolate CBECC1 showed 100% identities with β-tubulin gene sequences of Pyricularia sp. isolated from Cenchrus echinatus.