Abstract

IN-VITRO EVALUATE ANTAGONISM STRAINS OF ACTINOMYCETES ON GROWTH STRAINS OF RHIZOBIUM

Abdouslam M. Rassem* and Arun A. David

ABSTRACT

The work evaluates the antagonism between strains of Actinomycetes and strains of Rhizobium, soil samples were collected from field pea nodules area, actinomycetes and rhizobium strains were isolated and cultured on selective media, three strains of both actinomycetes and rhizobium were isolated, identified using morphology and biochemical properties, the isolates identification was confirmed by molecular method of 16S rRNA gene amplification. Thus the six isolates were identified as rhizobium (RS1-leguminosarum, RS2- Sinorhizobium meliloti and RS3-Rhizobium pusense) and actinomycetes (AS1- Streptomyces lucensis, AS2-Streptomyces griseus and AS3- Streptomyces olivaceus) the antagonistic assay was done using dual culture method in nine combinations of actinomycetes and rhizobium isolates. Out of nine combinations of antagonistic assay, eight combinations showed that Actinomycetes executes an inhibitory effect on growth of rhizobium strain, only one combination (AS3 against RS3) showed a reverse effect where rhizobium isolates (RS3) had higher zone of growth than actinomycetes isolate (AS3) The antagonistic action of streptomyces griseus (82%) and streptomyces olivaceus (71%) were maximum against rhizobium pusense, 18% and Sinorhizobium meliloti 29% respectively while other species showed varied but lower activity than these two actinomycetes species.

Keywords: Antagonistic assay, isolates, actinomycetes, rhizobium, dual culture, field pea.