Morphological and molecular characterization of Pyricularia oryzae isolates causing wheat blast in Bangladesh

Pyricularia oryzae tritici , one of the most notorious pathogens of wheat, is a major biotic threat in wheat production around the globe. A total of sixteen P. oryzae tritici isolates isolated from four major wheat blast affected districts viz ., Meherpur, Chuadanga, Kustia and Jhenaidaha of Bangladesh were analyzed. Considerable morphological variations in terms of colony color, texture, surface appearance, conidial size and growth pattern were observed. Molecular characterization of the isolates was done based on the sequence information of internal transcribed spacer (ITS) regions. Phylogenetic analysis based on ITS sequences of all the isolates of this study along with 18 reference Pyricularia isolates of different countries (retrieved from NCBI) revealed that isolates belonging to same district of Bangladesh did not form same cluster in the dendrogram. Again, Bangladesh— P. oryzae tritici isolates showed close relationship with other wheat infecting reference isolates from different countries. Isolates infecting other than wheat showed host specific clustering and distantly clustered in the phylogenetic tree. Findings of this study will be helpful for better understanding of this newly evolved pathogen in Bangladesh.