1Division of Medicinal Aromatic & Economic Plants, North East Institute of Science & Technology (CSIR), Jorhat-785 006, Assam, India.
Division of Plant Physiology, Indian Agricultural Research Insitutte, New Delhi-110 012, India.
*Corresponding author, E-mail: tellvanita@yahoo.co.in.
The para-nodulated maize plants grown in soil supplemented with Azospirillum thrice during the growth period performed better than the control plants. The para-nodules were formed along primary roots in the presence of 2,4-dichlorophenoxyacetic acid (2,4-D) and Azospirillum. The content of the endogenous hormones viz. indole acetic acid (IAA) and gibberellic acid (GA) was enhanced in paranodulated maize plants cultivar Kiran. However, the level of abscisic acid (ABA) declined. The dry weight and leaf area of the para-nodulated plants increased as compared to the control plants. The ammonia concentration (56% more) and nutrients were higher in the para-nodulated plants as compared to the control plants. The soil nitrate and ammonical N levels were higher in the pots with treated plants and inoculated with Azospirillum as compared to their levels in control pots. Bacterial phytohormone synthesis seems to be responsible for the Azospirillum mediated plant growth promotion.
Biofertilizers, gibberellic acid, indole-3-acetic acid, nitrogen, para-nodules, Zea mays
