A NOVEL PROCEDURE FOR RAPID ISOLATION OF PLANT-GROWTH PROMOTING PSEUDOMONADS

A rapid and novel procedure for the isolation of plant growth promotin g rhizobacteria (PGPR) is described. This method entails screening soi l bacteria for the ability to utilize the compound 1-aminocyclopropane -1-carboxylate (ACC) as a sole N source, a trait that is a consequence of the presence of the activity of the enzyme ACC deaminase. This tra it appears to be limited to soil bacteria that are also capable of sti mulating plant growth. Seven different soil samples from two geographi cally disparate locations were found to contain pseudomonads that were able to to utilize ACC as a N source. Each of the seven strains was s hown, by the ability of the bacterium to promote canola seedling root elongation under gnotobiotic conditions, to be a PGPR. The method desc ribed here may be used to replace the otherwise slow and tedious proce ss of testing individual bacterial strains for their ability to promot e plant growth, thereby significantly speeding up the process of findi ng new PGPR.