LONG-TERM INFLUENCE OF SOIL AMENDMENTS ON GERMINATION OF CONIDIA

Publisher Website
Google Scholar
Abstract
Washed conidia of Gliocladium fimbriatum and Fusarium solani f. phaseoli required a carbon and nitrogen source for complete germination. Filtered aqueous extracts and membrane-expressed soil solution supported germination of washed conidia of both fungi, but germination of G. fimbriatum was completely inhibited in non-filtered aqueous soil extracts and on soil–cellophane–agar plates, whereas conidia of F. solani f. phaseoli germinated readily in both instances.The long-term influence of certain soil amendments on the capacity of the soil solution to support germination of conidia was investigated. Inhibition of germination of conidia of F. solani f. phaseoli and G. fimbriatum in filtered aqueous extracts of cellulose-amended soil with a C/N ratio higher than 25/1 and barley-amended (C/N ratio, 55/1) soil was overcome by the addition of 5 p.p.m. nitrate nitrogen to the soil during extraction. Chemical analysis of cellulose-amended (C/N ratio, ∞) soil indicated that most of the inorganic nitrogen had been immobilized. Germination in aqueous extracts of soybean- (C/N ratio, 7/1) and alfalfa-amended (C/N ratio, 18/1) soil or non-amended soil was not inhibited. Germination of F. solani f. phaseoli conidia added directly to cellulose-amended (C/N ratio, ∞) soil in 2% sucrose solution was also inhibited, whereas conidia added in 2% sucrose to non-amended soil germinated readily. Cellulose-amended (C/N/P ratio, 25/1/0.1) soil was the only soil that consistently demonstrated fungistatic activity to germination of conidia of F. solani f. phaseoli on soil–cellophane–agar plates. Membrane expressed soil solutions of the cellulose-amended soil, however, did not demonstrate fungistatic activity to germination of conidia.

This publication has 2 references indexed in Scilit: