Ecology of soil fungi in paddy field of Tamilnadu-Thanjavur District

摘要

Soil is a complex ecosystem, delimited by physicochemical parameters that hold enormous number of living organisms. This study deals with the seasonal and depthwise variations in soil fungal population in relation to the soil nutrient variablility in one of the least studied traditional Paddy field in Thanjavur district, TamilNadu viz Nadur, Orathanadu, Punnainallur and Tholkappiyar Square. About 30 different species belonging to Ascomycetes and Phycomycetes were isolated by using PDA medium and identified by using Standard Manual. Nonetheless, Fungal counts were greater in the surface (SS-10cm) layer of the soil as compared to others. During rainy season, maximum fungal count was, recorded in the subsoil layer (8-10cm). The dominant species were Aspergillus niger, Cunninghamella sp. followed by T.viride, T.harzianum Penicillium janthinellium, P.claviforme, A.terreus and Aspergillus conecium from the paddy field soils of Nadur soils in various seasons whereas, in Orathanadu soils the dominant species were A.niger, Curvularia sp. followed by Aspergillus conecium, A.oryzae, F.oxysporam, P.janthinellium and Trichoderma koeningii. In Tholkapiyar sadhukam, the dominant species were A.niger, T.viride, T.harzianum followed by P.janthinellium ,Penicillium citrinum and Rhizopus sps. whereas in Punnainallur, the dominant species were A.niger, T.harzianum and Cunninghamella sp. followed by F.oxysporum, P.claviforme, P.janthinellium, Trichoderma koeningii and T.viride respectively.