Biochemical changes in Mucuna sloanei (ukpo) seeds induced by six pathogenic fungi and comparative analysis of the pathogenic fungi

Abstract

Biochemical changes in Mucuna sloanei Fawc. & Rendle (Fabaceae) seeds induced by six pathogenic fungi and comparative analysis of the pathogenic fungi were investigated. The fungal pathogens isolated from partially rotted seeds of M. sloanei seeds include Rhizopus stolonifer, Aspergilus flavus, Aspergillus niger, Penicillium italicum, Alternaria altermata and Fusarium oxysporum. These fungi were used as test fungi to inoculate healthy M. sloanei seeds aseptically. The results of proximate analysis in (%w/w)/100 g of seeds inoculated with the test fungi and uninoculated (control) seeds carried out revealed that there was a significant increase (P < 0.05) in moisture, ash, lipid and carbohydrate content of seeds inoculated with the test fungi, relative to uninoculated (control) seeds. While fiber and protein content decreased in fungi inoculated seeds relative to uninoculated seeds. There was a significant difference (P < 0.05) in mineral content evaluated. Calcium, phosphorus and sodium increased in seeds inoculated with the test fungi relative to the uninoculated, while iron, potassium and magnesium decreased in seeds inoculated with the test fungi. Phytochemical (anti-nutrient) contents (tannin, saponins, total oxalate and cynogenic glucoside) increased in the fungi inoculated seeds, relative to uninoculated seeds. Significant differences also occurred among the test fungi. Fusarium oxysporum, Alternaria altermata and Penicillium italicum appeared to induce more changes in proximate and mineral composition. Penicillium italicum also recorded the highest increase in phytochemical content (tannin, saponin and total oxalate) in seeds inoculated with test fungi relative to the uninoculated (control) seeds.