Isolation and characterization of Streptomyces spp showing antagonistic activity against fungal pathogens effecting soybean crop
Quasim Turiki, Merakanapalli Kishore Babu, Kunchala Rajyalakashmi, VE Vijaya Sekhar, Syed Shabana, A Krishna Satya
A total 93 cultures of Actinomycetes were screened for their antagonistic activity against major fungal pathogens of soybean crop. Viz., Colletotrichum lindemuthianum, Fusarium oxysporum, and Rhizoctonia solani. Dual culture assay was performed. Glucose Casaminoacid yeast extract agar (GCY) plates were prepared. A 5mm fungal discs were placed on the one edge (1cm from the corner) with Actinomycetes streaked on the other edge of the plate (1cm from the corner) followed by incubation at 28 ± 2°C for four days. Control plate growth has covered the whole plate. The inhibition of fungal mycelium was measured as the distance of inhibition in cm. All the plates were maintained in triplicates and mean values were taken. Three isolates namely NAVS13, KNSS3, CHSS3 inhibited C. lindemuthianum, F. oxysporum, and R. solani. The isolates were further evaluated for Cellulase, Lipase, Protease, HCN, phosphate solubilization, production of growth hormone IAA, production of Siderophore, Chitinase, β-1, 3-Glucanase, and physiological properties. The isolates were subjected to molecular characterization and identified as Streptomyces rochei, Streptomyces cavourensis and Streptomyces alfalfa.