Identification of Antifungal Compounds from Solanum torvum Against Post Harvest Anthracnose of Banana

The fungitoxic effect of 25 botanicals belonging to 17 different families was evaluated against Colletotrichum musae (Berk. & M. A. Curtis) Arx causing banana anthracnose disease. Among all, Solanum torvum showed the maximum antifungal activity followed by the Allium sativum × Allium cepa (Zimmu) and Adenocalymma alliaceum. Post-harvest treatment of banana fruits with leaf extracts of S. torvum, zimmu, and A. alliaceum in room and cold storage condition significantly reduced the disease incidence and also de novo synthesis of defense related Peroxidase (PO) and PolyPhenol Oxidase (PPO) compounds. Of all the leaf extracts, S. torvum showed the least incidence of disease with highest activity of defense related compounds. An attempt was made to identify the antifungal compounds through chromatographic techniques like TLC and RP-HPLC. Different leaf extracts of S. torvum were obtained using different solvents and evaluated fungitoxic effect against the pathogen in vitro. Acetone was found the best in extracting the bioactive antifungal compounds from S. torvum. Further TLC analysis showed the presence of phenolic compound and development of blue spot at Rf 0.65 and eluted purified blue spot exhibited a maximum inhibition of the pathogen in vitro. The presence of syringic acid was evident from the RP-HPLC analysis. The results seem to be the new report for the presence of phenolic compounds in the leaf extract of S. torvum. The botanical Solanum torvum could be used as botanical fungicide, as an alternative to synthetic fungicides to manage the disease effectively.