Characterization and evaluation of actinomycete isolates for traits associated with plant growth promotion

Abstract

Eighty five isolates of actinomycetes were isolated from different sources viz., decayed wood, compost dumped soil, and mangroves of North Karnataka and were tested for the typical traits of plant growth promotion. The isolates exhibited varied potential of siderophorogenesis and cyanogenesis. Indole 3-acetic acid (IAA) produced by the isolates ranged from 6.88 to 20.22 µg ml-1.The potent isolates A-34 and A-57 which exhibited maximum ability to produce siderophore, hydrogen cyanide (HCN) and Indole-3-acetic acid were characterized by 16S rDNA sequencing and revealed maximum similarity to the genus Streptomyces. Thus the isolated Streptomyces strains with plant beneficial traits have potential for use in sustainable agriculture.