Antifungal activity of rice associated phyllosphere (RAP) communities against brown spot of rice (Bipolaris oryzae)

Abstract

The brown spot of rice is a devastating disease in rice production. It is caused by the pathogen Bipolaris oryzae which reduces many quality and quantity impacts on the rice crop. It has been known well that some phylloplane bacterial antagonists are antagonistic to some foliar diseases. The research work was carried out with the aim to study the antagonistic property of phylloplane antagonists of rice against B. oryzae. Twenty phylloplane bacterial antagonists were isolated and characterized. The bacterial antagonists Bacillus subitilis and Pseudomonas fluorescence were identified by the biochemical tests. Among the bacterial isolates, the isolate PI (Bs) 5 recorded 52.96 per cent inhibition of the mycelial growth of the pathogen over control. It was followed by PI (Pf) 1, PI (Pf) 2 and PI (Bs) 8 which recorded 52.59, 52.22 and 49.26 respectively. The minimum inhibition was exerted by the isolate PI (Bs) 9 followed by PI (Pf) 17 which recorded 19.26 and 19.63 per cent inhibition respectively.