Abstract

Okwulehie, Ikechukwuka Cyriacus* and Alfred, Nnamdi Kingsley

Anona muricata commonly known as sour-sop, belong to the family Annonaceae. It is a small slender tropical tree usually grown for its large fleshy and juicy fruits. The fruit of A. muricata plays an important role in the diet of many in many parts of the tropics including Nigerian. Unfortunately, the usefulness of the fruits of Anona is decimated by many fungi species. Investigation of the fungi that cause the deterioration of sour-sop (Anona muricata) was carried out in order to recommend the appropriate control measures. Mature fruits of A. muricata were collected from different locations in Abia State. Isolation, characterization and identification of fungi were made by plating washings from skin surface and extracted juice from pulp of the fruits in test tubes containing potato dextrose agar (PDA) and yeast malt extract agar (Difco) into which streptomycin sulphate was incorporated to inhibit bacterial growth. Inoculated tubes were incubated at 28 ± 2°C for 48 h. Control experiment was carried out with sterile peptone water instead of using the washings. The following filamentous and yeast fungi were isolated from the skin surface and pulp of the fruits: Aspergillus flavus, Aspergillus niger, Botryodiplodia theobromae, Colletotrichum sp., Fusarium solani, Mucor sp., Penicillium chrysogenium, Penicillium sp., Rhizopus stolonifer and Rigidoporus sp., Candida albicans, Saccharomyces cerevisiae, Saccharomyces rouxii and Torulopsis spp. The pathogenicity tests of the filamentous fungi isolated were carried out on mature green Anona fruits and were found to be pathogenic. The filamentous fungi were mainly responsible for the deterioration of the fruits of A. muricata in Abia state while the yeasts were fermentative.