Pathogenicity and cell wall-degrading enzyme activities of some fungal isolates from cowpea (Vigna unguiculata [L] Walp)

Abstract

Nine fungal species isolated from cowpea seeds were used as inocula on four cowpea varieties commonly distributed to farmers in Ilorin, Kwara state, Nigeria by the National Seed Service, a subsidiary of the Federal Ministry of Agriculture and Natural Resources. The effects of fungi on germinability and seedling health were determined using seedling symptom test. Two of the virulent species were screened for the production of cell wall degrading enzymes using viscometric method. All the fungi reduced germination rate in all the cowpea varieties and different types of seedling symptoms were noted for the fungi. The symptoms included seed rot,
chlorotic leaf development, stunted growth etc. Production of pectinases and cellulases by Aspergillus flavus and Penicillum sp. was observed and the virulence of the two organisms could be attributed to the activities of these cell wall degrading enzymes.