Physiological and nutritional variability of different Pyricularia grisea isolates isolated from various hosts inciting blast disease of rice

Different isolates of Pyricularia grisea from rice (RPg), Panicum grass (PPg) and finger millet (FPg) were isolated for variability study of the pathogen. Pyricularia grisea was grown on nine different solid media viz., Potato dextrose agar, Potato sucrose agar, Czapek’s dox agar, Sabouraud agar, Richard’s medium, Potato carrot agar, Panicum leaf extract agar, Rice leaf extract agar and Oat meal agar to study the cultural characteristics of the pathogen. Oat meal agar supported maximum radial growth (83.33 mm) followed by Potato dextrose agar (70.17 mm) and Potato carrot agar (66.17 mm) in case of rice blast. In case of P. grisea from Panicum and finger millet, PDA supported highest radial growth of 84.00 mm and 82.50 mm respectively followed by Potato sucrose agar (83.33 mm and 80.33 mm) respectively. Highest radial growth of the pathogen (70.13 mm) was found at 30 0C followed by 25 0C (61.88 mm). Sodium nitrate produced highest growth of mycelial dry weight (12079.0 mg) followed by ammonium oxalate (4971.0 mg).