Studies on certain aspects of root surface fungi 2. succession of fungi on decomposing pennisetum typhoides
Acta Mycologica 17(1-2): 27-40
Sixty-seven fungal species from the nonrhizosphere (NR), rhizosphere (RS) and cortical (RPC) and stelar (RPS) parts of the crown (RC), middle (RM) and distal (RD) regions of decomposing roots of P. typhoides (Burm. f.) Stapf. et Hubb. were isolated during Dec.-June, 1970 to 1972. The number of fungal species gradually decreased from NR-RPS in horizontal and RC-RD in vertical regions. The fungal population was always higher in RS of different depths than in corresponding NR regions. The amino acids and sugar components of the roots showed a direct correlation with the fungal population. The amount of cellulose, hemicellulose and lignin components of roots gradually decreased from Dec. to June. Root washings collected from RC, RM and RD regions contained vanillic acid and 3,4-dihydroxy benzoic acid during March and April; these exerted an adverse effect on the rhizosphere fungi during this period. The pH and moisture contents showed poor correlation with the fungal population except during summer months. Phycomycetes and Deuteromycetes obtained in the first phase were followed by Deuteromycetes along with few Ascomycetes in the 2nd phase. In the last phase Deuteromycetes with some sterile mycelia were isolated. Aspergilli were the most numerous throughout the investigation.