Role of cellulose decomposing fungi on azospirillum-maize association

ABSTRACT

A greenhouse pot experiment and sand cultures were used to examine the possible role of cellulose decomposing fungi in Azospirillum-maize association. Soil amendment with 0.2% straw and inoculation with Azospirillum lipoferum [strain Z 4/1] gave the highest densities of Azospirillum in the histosphere of maize plants and higher growth parameters. Other diazotrophic bacteria of plant free soils were stimulated with a straw amendment. Fifteen genera and 22 species of cellulose decomposing fungi were isolated on cellulose-Czapek's agar medium from pots amended with straw. The total count of these fungi increased significantly with straw amendment. The most common cellulose decomposers were Aspergillus niger, Penicillium funiculosum and Trichoderma harzianum. In sand cultures amended with straw, nitrogenase activity, total nitrogen, residual and straw utilized by co-cultures of Azospirillum brasilense [strain R6/1] and cellulose decomposing fungi were studied