Abstract

Plant growth promoting rhizobacterias (PGPRs) are free living soil bacteria that colonize root surfaces and have the capacity to enhance plant growth directly or indirectly. A total of 23 bacterial strains were isolated from saffron rhizoshere soil during the flowering stage of corms. All these isolates were screened for their plant growth promoting traits like production of IAA, phosphate solubilisation activity and siderophore production. The maximum percentage of the bacterial isolates was of Gram negative rod shaped type. A total of six isolates were capable of showing one or more than one of the activities like IAA production, Siderphore production and phosphate solubilisation activity. The Bacillus subtilis showed highest IAA production of 360 µg/ml while as Pseudomonas ssp., was found to be highly efficient in terms of phosphate solubilisation production (460 µg/ml) and siderophore production (62%). It was concluded from the results that these rhizobacterial strains isolated could be a promising source for plant growth promoting agent in increasing the growth of cormlets vis a vis enhancing the yield of saffron.

Key words: IAA, PGPR, phosphate solubilisation, rhizosphere, siderophore, saffron.

Abbreviation

IAA, Indole acetic acid; PGPR, plant growth promoting rhizobacteria;PSB, phosphate solublising bacteria.