Evaluation of the performance of indigenous azospirillum of the plant growth under pot culture from Madurai district

Azospirillum is the foremost common plant growth-promoting rhizobacteria (PGPR) that are generally associated with fibrous root containing plants viz., rice, wheat and Ragi. Azospirillum is a nitrogen fixing bacterium and secretes plant growth hormone like IAA, Gibberellin which helps in plant root growth. The performance of Azospirillum will be varying for different location due to its adaptability to the particular environment. In this experiment, the indigenous strains were isolated from rice. The isolates were purified, characterized, screened and massmultiplied on N free malic acid (Dobreiner, et.al, 1976). The screened isolates were subjected to pot culture condition. The effect of the isolates on plant root length, shoot length, dry weight, no of main and lateral roots were examined at 10, 20 and 30 DAS. Among the isolates isolate AI7 gave better performance towards root length (18 cm), shoot length ( 35 cm), root volume (0.19 cc), number of main root ( 16 ) and number of lateral root (15.64) and dry weight (0.64g/plant).