Abstract
Inoculation of maize seedlings with 107 colony forming units (cfu) of Azospirillum plant-1 significantly increased the root surface area 2 weeks after sowing as compared to non-inoculated plants. Indole-3-acetic acid (IAA) was identified by gas liquid chromotography (GLC) and gas chromatography-mass spectrometry (GC-MS) in Azospirillum tryptophan-free culture medium. The amount of IAA in the medium was calculated from the gas chromatogram by isotope dilution analysis and found to be 32-40 ng ml-1. Roots of Azospirillum-inoculated maize seedlings were found to have higher amounts of both free and bound IAA as compared to control. The amount of free IAA significantly increased in the inoculated roots 2 weeks after sowing. IAA and indole-3-butyric acid (IBA) were identified by GC-MS only in the roots of Azospirillum-inoculated seedlings 2 weeks after sowing. The significance of the higher amounts of IAA following inoculation with the bacteria is discussed.
Original language | English |
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Pages (from-to) | 147-153 |
Number of pages | 7 |
Journal | Soil Biology and Biochemistry |
Volume | 21 |
Issue number | 1 |
DOIs | |
State | Published - 1989 |