Abstract:
Azospiritium, the nitrogen fixing bacterium associated with the root
system in pear! millet (Pennisetum americanum) has been studied for the phytohormone
production. Both the wild types of Azospirillum and the drug resistant
mutants produced phytohormones like indole acetic acid and gibberellin like substances.
Addition of the precursor tryptophan and aerated conditions of incubation
helped the production of more IAA and GA. The isolates varied in their ability
to produce the phytohormones. Seeds of pearl millet inoculated with Azospirillum
resulted in profuse root hairs and lateral root development. Moreover inoculation
resulted increase in the vigour index of the plant.
