Endophytic movemnet and phylloplane survival of P. fluorescens in rice

Abstract

Fluorescent Pseudomonads belong to plant Growth Promoting Rhizobacteria (PGPR), the important group of bacteria that play a major role in the plant growth promotion, induced systemic resistance, biological control of pathogens etc. Many strains of Pseudomonas fluorescens are known to enhance plant growth promotion and reduce severity of various diseases. The aim of this investigation was to assess the systemic movement and phylloplane survival of P. fluorescens (PF9) in rice crop after treated with PF9 as seed treatment and foliar spray @ 10ml/kg and 0.5% concentration respectively under green house condition. The results clearly revealed that systemic movement of bacterium (PF9) could be recovered in roots up to 75 days (3.8×103) the maximum period tested, where as in stem and leaves the population declined with increase in the sampling period and the bacterium could be recovered only up to 60 days after sowing the seeds treated with bacterium. Maximum population of the test bacterium could be detected in root (6.8×103), stem (5.6×103) and leaves (4.1×103) at 15 days after sowing indicated the necessity for subsequent application of the antagonist. Also, the population of bacterium in the phylloplane and leaf tissues after foliar spray showed a declining trend with increase in the sampling period. The maximum population (18.2×103) on phylloplane and population in leaf tissue (4.9×103) was recorded on the first day after foliar spray and then the population showed a gradual decline and reached the minimum population in the phylloplane (0.6×102) and in the leaf tissues (0.3×103) at 12 days after spraying.