The bioinoculation effect of two different formulations of COI and biofloc of B. mucilaginosus isolates viz., SSB-8, SSB-11 and SSB-17 together with supplementation of rice residues viz., rice straw, rice husk, and black ash on the induction of systemic resistance against Pyricularia oryzae in lowland rice was studied under pot culture conditions. It was observed that the individual application of B. mucilaginosus cells viz., either COI or biofloc altered the biochemical and physiological parameters viz., reducing and non-reducing sugar levels, total phenol content and defense enzymes activities, such as peroxidase (PO), polyphenol oxidase (PPO) of rice plant to a higher level when compared to control. However, the application of B.mucilaginosus cells as bifoloc was found to augment the above parameters to a higher level when compared to co-inoculation of the same isolates of B.mucilaginosus isolates. Interestingly, the effect was more pronounced during the supplementation of rice residues along with B.mucilaginosus inoculation. Among the different rice residues tested, rice straw, supplementation augmented the systemic resistance of lowland rice against Pyricularia oryzae to a higher level when compared to rice husk and black ash supplementation, the treatment comprising of biofloc formulation of B.mucilaginosus isolates together with supplementation of rice straw @ 5 t ha-1 induced the systemic resistance of lowland rice against P. oryzae to the highest level when compared to other treatments. The effect was more pronounced during the supplementation of silicon rich, rice residues along with the application of B.mucilaginosus bioflocs. Hence, it is proposed that the application of SSB isolates, as biofloc formulation, together with supplementation of rice straw @ 5 t ha-1 might be followed for the maximization of ISR in rice P. oryzae pathosystem under lowland condition. It has been postulated that the EPS biosynthesis of SSB cells during the biofloc processes might act as an elicitor for the enhancement of ISR in rice P. oryzae pathosystem.
