The role of osmotolerant rhizobacteria in rice growth under different drought conditions

Osmotolerant rhizobacterial isolates were used as inoculants for rice under different drought conditions in a greenhouse. Rice was grown on a Regosol, under either sterile or non-sterile conditions, in which the water level was adjusted to 80% and 40% of field capacity. Rice seed was inoculated with osmotolerant rhizobacterial isolates (isolates Al-19, A82, and M7b) and grown until the plant reached maximum vegetative phase (86 days from seed sowing). Inocula used were: Al-19 plus A82, Al-19 plus M7b, A82 plus M7b, and a mixture of 3 isolates. Under sterile conditions, inoculation of rice with the different inocula resulted in an increase in shoot dry weight, root dry weight, and number of tillers of 0–45.72%, 0.62–79.67%, and 0– 61.11%, respectively. Under non-sterile condition, shoot dry weight, root dry weight, and number of tillers increased by 19.66–28.04%, 14.00–91.33%, and 14.29–157.14%, respectively. The study also demonstrated that the role of osmotolerant rhizobacteria was more pronounced at 40% field capacity than 80% field capacity.