Cultural, Morphological and Biochemical Variability Studies among the Isolates of Alternaria solani, the Causal Agent of Early Blight Disease of Tomato

Present experiment was conducted at College of Horticulture, Bengaluru (KA) during year 2017–18 to study the cultural, morphological and biochemical variations among isolates pathogen Alternaria solani, causal agent early blight disease in tomato. The results revealed variation collected from different regions Karnataka state, India with regard colony characteristics viz., colour, mycelial growth pattern, margin zonations whereas maximum terms diameter (90 mm) observed Bagalkot (BaBG) Chikkamagaluru (CMH) on Czapek’s (Dox) agar medium while least (36.33) noticed Bidar (BiHH) isolate. isolate could grow better as 3 media tested produced 80.70 mm (63.70 V-8 juice agar. studies that all conidia various varied length (25.07–42.90 µm), breadth (10.53–21.52 µm) number horizontal septa (2–7), longitudinal (0–4). Biochemical significant their enzyme activities. peroxidase activity more Chikamagaluru (81.80 Unit g-1 FW) found 11.78 FW esterase (BYC) (69.01 FW. Existence solani evident obtained.