Impact of ethanol and chloroform extract of Terminalia chebula seed on early blight pathogen

Early blight is a very common and devastating fungal disease of crops that imposes economic loss throughout the world. Spores of Alternaria solani present in the soil for many months to year make it tough to control. When weather suitable, spores germinate to form mycelium affecting plants, initially leaves near the land or soil affected which leads to fruit rot in tomatoes and tuber rot in potatoes. In this study, the antagonistic activity of Terminalia chebula seed was evaluated for its ability to control Alternaria solani and is it really an alternate candidate for synthetic fungicide. Dried fruit seeds of Terminalia chebula extracted with ethanol and chloroform resultant extract were tested for their biological activity by a broth macro dilution method to check spore germination and a well-diffusion method was used to control mycelial growth of Alternaria solani. Ethanol extract (P<0.010) and chloroform extract (P<0.012) had significant levels of controlling early blight spores. Ethanol extract 20.13mm and chloroform extract 13.9mm zone of mycelial inhibition recorded. Advance studies were carried out on ethanol extract by GCMS and Seed germination to test biological activity. GCMS analysis found 20 active peaks with two of them being new, remaining 18 known compounds identified with their retention time and peak area compared in the NIST library. Structural elucidation was done for 5-Hydroxymethylfurfural, cis-9, cis-12-Octadecadienoic acid, Cis-13-Eicosenic acid and n-Hexadecanoic acid. Seeds of Lycopersicum esculentum treated with ethanol extract increase the germination rate, vigor index, and percentage of germination. The phytochemical compound present in ethanol extract increases protein and protease activity in germinating seeds, a better alternate for synthetic compounds controlling plant pathogenic fungi Alternaria solani at 0.1mg/ml.