Abstract

PLANT GROWTH PROMOTING ACTIVITY OF AZOSPIRILLUM ISOLATED FROM PADDY FIELD OF KANKOL, KANNUR DISTRICT

Divya P. Easwaran*, Dharanya Krishnan M., Sumesh K., Aneesh K. and Sanila C. V.

Abstract

Azospirillum sp are the gram negative rhizobacteria, which are found in association with plant roots, especially with Maize, Rice and other plants.The aim of the study was to isolate Azospirillum sp. from Rice plant root (Oryza sativa var IR 20) collected from paddy field of KANKOL. The phenotypic characterization of the isolates based on the Bergey’s manual of Determinative Bacteriology, carrying out microscopy (morphology) Gram’s staining. The isolates were cultured on N-Free malate medium developed by Dobereiner. The growth and metabolisms of bacteria were indicated by the color change in the medium from green to blue due to the production of metabolic end products. In this study the isolates were assessed for their Plant Growth Promoting Activity (PGPR) activity by demonstration of IAA production and GA production, siderophore production, Nitrate reductase activity study. The PGPR activity indicate the isolates of Azospirillum sp also be used as a biofertilizer and the Nitrate reduction activity improves the quality of grains along with growth promoting activities of microbes improves growth rate of plant.

Keywords: Azospirillum sp, Oryza sativa var IR 20, PGPR activity, IAA and GA.