Abstract

Arbuscular Mycorrhizal (AM) fungi are of considerable interest because of their ability to form symbiotic associations with various crops species. This study was carried out to find the occurrence and abundance of AM fungi in agricultural fields of Madurai district. Different AM fungal spores were isolated from the rhizosphere soil along with the roots of different crops growing in this region. Soil samples in this region exhibit varied physico-chemical parameters which correlate with Arbuscular Mycorrhizal Fungi (AMF) infection and spore count. The highest number of spore count (410±1.15) and high infection percentage (80.1±1.07 %) were found in maize grown under Mellur (MLR1) tract. The lowest number of spore count (152±1.53) and infection percentage (30±0.40 %) were observed in upland rice grown under Thirumangalam (TMQ) tract. Five AMF genera including Glomus, Gigaspora, Scutellospora,Entrophospora and Acaulospora were identified from the rhizosphere soil collected from the maize crop cultivated at Mellur. Genus Acaulospora and Glomus were found to be very dominant in maize crop. The results suggest that spore density in soil and root infection percentage varied from one tract to another tract and higher AM infections rates were observed in soil with low phosphorus content.

Keywords: AM fungi, spore count, infection percentage, soil parameters