Abstract

PLANT GROWTH PROMOTING STUDIES ON AGROBACTERIUM AND RHIZOBIUM SPECIES ISOLATED FROM ROOT NODULES OF VIGNA MUNGO (L. HEPPER)

Darsi Phebe Sarah Koti Ratnam*

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Abstract

The present study ten bacterial strains were isolated from root nodules of Vigna mungo, commonly known as black gram. The seeds were collected from national scientific corporation, Guntur. The seeds were sown in the earthen pots of botanical garden of our college and the nodules were collected from every ten days interval. Maximum size of the nodules was selected for isolation. After the preliminary and biochemical characterization the ten strains were identified as 5 Agrobacterium and 5 Rhizobium species. All the isolates were tested for plant growth promoting characters like IAA, Gibberellic acid production, Siderophore production. Out of ten isolates tested, only one isolates i.e. Agrobacterium Sp-5 showed potential activity of Indole Acetic Acid (35.5 μg/ml) Gibberellic acid (28.3 μg/ml) and Siderophore production (26.5 μg/ml) respectively. Various factors like suitable pH 7.0, optimum temperature 30°C and 48 h of incubation periods influence the production. These plant growth promoting abilities can make this isolate a potential PGPR candidate for its application in sustainable agriculture.

Keywords: Agrobacterium, Rhizobium, Gibberellic acid (GA3), Indole Acetic Acid (IAA), Siderophore.