The role of seed-borne Aspergillus flavus link ex Fr., Aspergillus niger Van Tiegh and Macrophomina phaseolina (Tassi) Goid on deterioration of groundnut ( Arachis hypogaea L.) seeds

Abstract

The role of seed-borne Aspergillus flavus Link ex Fr., A. niger van Tiegh and Macrophomina phaseolina (Tassi) Goid on the nutritional levels of groundnut ( Arachis hypogaea L.) seeds was investigated. Significant increases ( P = 0·05) were observed in the moisture content, free fatty acid and protein content of seeds inoculated with the fungi as compared with uninoculated seeds. A. flavus, A. niger and M. phaseolina increased the moisture content 12·1%, 25·3%, 20·4%, fatty acid content 55·5%, 35·8%, 13·9% and protein content 4·0%, 1·5% and 4·3% respectively in seeds incubated for 7 days at 25° C ± 2° C. The three fungi caused reduction in oil, dry matter and carbohydrate contents. A. flavus caused a loss of 2·3% oil, 12·1% dry matter and 4·5% carbohydrate; A. niger an oil loss of 3·6%, dry matter loss of 25·3% and carbohydrate loss of 0·3%, while M. phaseolina caused 1·7% loss of oil, 20·4% loss of dry matter and 0·1% loss of carbohydrate in seeds incubated for 7 days. A. flavus and A. niger produced an increase of 0·9% and 1·1% in ash and 1·9% and 0·3% in fiber respectively while M. phaseolina caused a decreased of 0·7% and 1·8% in ash and fiver contents respectively in seeds incubated for 7 days. These increases and decreases in nutritional levels of the seeds were found to be significant ( P = 0·05) when compared with the controls. Similar results were observed in seeds inoculated with the fungi and incubated for 14 and 21 days at 25° C ± 2° C.