Cultural and Morphological Variability of Alternaria Lini Isolates Causing Blight of Linseed

Alternaria lini causes blight of linseed in India. The leaves showing typical symptoms of Alternaria blight, in linseed collected from different part of country and characterized for cultural, morphological, pathogenic and molecular variations. Alternaria lini colonies varied in respect of their colony colour (whitish, light brown to dark brown), growth pattern (slow, medium to fast), appearance (cottony, fluffy, feathery to compressed & thin), radial growth (25mm to 60mm), shape (circular), margin (wavy, rough to smooth), zonation (presence or absence), and sporulation (early, medium to late). Morphological variation in average conidial length (23.26 to 45.72μm), width (6.76 to 17.01μm), number of septa (1.86 to 5.60) and presence or absence of beak (unbeaked, rudimentary beaked and short beaked) were observed. Average conidial size ranged between 24x7 to 46x17μm.