Morpho-cultural and pathogenic variability among isolates of Stemphylium vesicarium (Wallr.) E. Simmons, causing Stemphylium blight in onion collected from different geographical regions of Kashmir valley

摘要: Stemphylium blight is the most destructive disease of onion crop and poses a grave threat to very existence its cultivation in Kashmir. Thirty six (36) isolates vesicarium (Wallr.) E. Simmons were collected from different locations characterized for cultural, morphological pathogenic variations. Isolates produced velvety, cottony or fullfy colonies colours like whitish, light dark grey, olivaceous with greenish tinge brownish filliform, entire undulate margins. Significant variation colony diameter sporulation was observed among isolates. Mean hyphal width ranged 3.11 5.48 µm. Conidiophore length varied 20.07 92.56 µm. Similarly, mean conidiophore breadth 2.84 7.58 µm. either brown, brown colour. Conidial colour are ovoid, ovoid oblong shape. Transverse septation 0 6 longitudinal 5. Average ascus size varies 103.74–204.24 × 23.00–33.11 µm. ascospore 12.08–41.96 × 10.06–17.38 µm 3 7 6. Ascospores brown. In shape ascospores rounded base conical apex, both ends ellipsoidal. exhibited variations incubation period, number, lesions.