Effect of Various Culture Media on Cultural and Morphological Characteristics of Alternaria alternata

Alternaria alternate (Fries) Keissler. is one of the major constraints in the production of gerbera, causing heavy quantitative as well as qualitative losses. Results revealed that all the 10 culture media tested encouraged better mycelia growth and spore production of A. alternata. However, significantly highest mean mycelial growth was recorded on Potato Dextrose Agar (90.00 mm). The second and third best media found were Gerbera Leaf Extract Agar and Potato Malt Agar (each 82.50 mm). Rest of the culture media recorded radial mycelial growth in the range 32.50 mm (Yeast Extract Agar) to 75.84 mm (Malt Extract Agar). Most of the test culture media exhibited circular, initially white mycelial growth which later turned grayish. Potato DextroseAgar, Gerbera Leaf Extract Agar and Potato Malt Agar recorded excellent (++++) spore production; whereas, it was Good (+++) on Malt Extract Agar, Yeast Manitol Agar, Ashby's Manitol Agar and Corn Meal Agar. The media viz., Czepak's Dox Agar and Yeast Extract Agar exhibited fair (++) spore production.