Molecular Characterization and Phylogenetic Analysis of Magnaporthae oryzae B.C. Couch Causing Blast Disease of Rice (Oryza sativa) in Kashmir

Rice blast, caused by Magnaporthe oryzae B.C. Couch, is one of the major diseases of rice resulting in heavy economic losses. The present study, carried out during 2013–14, was aimed to characterize M. oryzae, isolated from Kashmir, on morphological characters and molecular basis using sequence information of ITS region of ribosomal DNA and to study its phylogenetic relationship with other sequences retrieved from GenBank, NCBI. Morphological characters, pathogenicity test and ITS sequence analysis helped in authentic identification of the pathogen. M. oryzae colonies were dull white to grayish-black with regular margins. Conidia were pyriform, hyaline to pale olive and measured 16–23 x 4–7 μm in size. In pathogenicity assay, typical blast disease symptoms were produced. The ITS sequence of M. oryzae (Kashmir isolate) showed 99% identity (E value: 0.00) with M. oryzae sequences already available in GenBank. The sequence was submitted to NCBI (GenBank Accession No. KP310498). Phylogenetic analysis revealed that KP310498 sequence was more closely related to the sequences of Chinese and Japanese isolates of M. oryzae as compared to Indian isolates. Moreover, most of the M. oryzae sequences under study were grouped according to the host species.