Evaluation of antagonistic activity of Pseudomonas spp. against Sarocladium oryzae causing sheath rot disease in rice (Oryza sativa L.)

Abstract

Sheath rot disease of rice (Sarocladium oryzae) has become a consequential production constraint in all rice growing countries. The pathogen was isolated from the sheath rot infected rice plants. In this study twenty isolates of Pseudomonas spp. were isolated from rhizosphere region of rice plants cultivated in southern districts of Tamil Nadu, India. These bacterial isolates were identified as Pseudomonas spp. by morphological and biochemical characterization. The isolates showed positive response for KOH test, oxidase, pigment production, siderophore and HCN production. The antagonistic potential of the twenty isolates of Pseudomonas spp. were tested against S. oryzae under laboratory condition. The results revealed that the Pseudomonas spp. isolate, PTN4 exhibited maximum inhibitory effect of 82.22 % and 78.89 % in dual culture and volatile compounds assay respectively over the control. Thus, the Pseudomonas spp. identified in this study can be utilized for the biological management of sheath rot disease in rice.