Evaluation of Biorational Compounds and Combinations Thereof Against Decay and Spoilage Microbes

Abstract

Salicylic acid (SA), a phytohormone, is a well-known signal molecule modulating plant immunity and plays a role in controlling plant development. Salicylic acid is a crucial plant hormone needed to develop a plant's tolerance to various diseases. SA is considered to be derived from two possible pathways; the ICS and PAL pathway, both starting from chorismite. Pre-harvest spraying, post-harvest fumigation, post-harvest dipping, and post-harvest coating are just a few ways SA and its derivatives preserve fruit. SA has been proven to be a naturally occurring plant hormone generally accepted as safe (GRAS) for use on fruit. SA and its derivatives have been shown to improve storage quality by reducing ethylene production and respiration rate, inhibiting fruit softening and color change, maintaining sugars, organic acids, and aroma, preventing chilling injury, fostering pathogen resistance, and activating the antioxidant system. In the present study, 28 endophytic fungi were procured on PDA plates from various plants like C. zeylanicum, C. roseus and S. oleracea. These cultures were subjected to production in potato dextrose broth for the production of salicylic acid by them. After preliminary analysis, two endophytic fungi #PALAM19 and #22CRSBRT procured from P. acerifolium and C. roseus showed maximum SA production and were further analysed. It was found that #PALAM19 and #22CRSBRT showed maximum production at 0.5mg/ml cinnamic acid at 26℃. #PALAM19 and #22CRSBRT were also tested for their antifungal activity against procured pathogenic fungi and it shows maximum zone of inhibition against Botrytis cinera. Procured #PALAM19 displayed the most potent antifungal activity between the two cultures as it shows clearance against all the procured pathogenic fungi but #22CRSBRT shows zone of clearance only against Aspergillus niger. Further studies on morphological and molecular identification of the potential endophytic fungi improvement in the production process need to be done.