SURVEY ON RICE BLAST AND MORPHOLOGICAL CHARACTERIZATION OF MAGNAPORTHE ORYZAE ON DIFFERENT CULTURE MEDIA

Abstract

ABSTRACT

Rice appears to be the most important food crop, accounting for a quarter of all calories consumed Rice blast is one of the most common significant obstacles to rice cultivation in any rice growing region of the world. Field survey on rice blast (Magnaporthe oryzae) was conducted in 30 field sites of Sonatola upazila belong to Bogura District during boro season 20192020.

Blast incidence and severity ranged from 0-81.8% and 0-65% respectively. The highest blast severity was recorded in Basmoti rice field of Pakulla village under Pakulla Union. Twenty (20) isolates of Magnaporthe oryzae was identified and morphologically characterized on Water Agar (WA), Potato Dextrose Agar (PDA), Potato Sucrose agar (PSA) and Oat Meal Agar (OMA). Radial mycelia growth rate of all isolates ranged from 5.5 to 22.5, 7.5 to 77.2, 5.5 to 61.5 and 7.5 to 72.5 in Water Agar (WA), Potato Dextrose Agar (PDA), Potato Sucrose agar (PSA) and Oat Meal Agar (OMA) respectively. Most of the isolates were blackish white in color, rough cottony surface structured and irregular shaped. Mycelial growth of Magnaporthe oryzae isolates significantly varied on different culture media.