Comparative Study on Phytochemical Properties and Antifungal Activities of Different Plant Extracts on Infected Fruit of Carica papaya

Abstract

The comparative studies of phytochemical properties and antifungal activities of different plant extracts; Ageratum conyzoides L., Phyllanthus amarus Schum. & Thonn, Senna alata (L.) Roxb. and Mangifera indica L. on infected fruit of Carica papaya was carried out using standard methods for analysis of all the tested parameters. The test was conducted using the selected plant extracts at five different concentrations (100 - 500mg/ml) against the isolated fungi. Molecular analysis was done to identify the isolated fungi. The results of the qualitative phytochemical screening revealed the presence of alkaloid, tannins, saponins, phenols and flavonoid in all the plant extracts. The quantitative phytochemical screening results showed varying quantities of alkaloids, tannins, saponins, flavonoids and phenols present in the extracts. The quantitative screening showed that A. conyzoides had the highest quantity of the constituents present in its extracts. Four fungal pathogens were isolated from paw-paw fruits and were identified as Rhizopus species, Aspergillus glavus, Aspergillus flavus and Penicillium species. The results of the antimicrobial assay on fungi isolated from infected pawpaw fruits showed that inhibition of fungal growth increased with a corresponding increase in concentration for all the fungal isolates. Penicillium species showed resistance to all the extracts. A. conyzoides showed the highest inhibition from 200mg/ml for the isolates followed by P.amarus. Molecular analysis identified the isolates as Rhizopus arrhizopus, R. delemar, R. oryzae and Aspergillus clavatus. The phylogenetic tree showed that Rhizopus oryzae, R. delemar, R arrhizus are closely related. A. conyzoides and P. amarus can be used to minimize the infection of paw-paw fruit by microbes.