Abstract

Indole-3-acetic acid (IAA) is an important plant growth regulator. As the very first endeavor, the study is aimed at extracting and quantifying IAA from seedlings of Bambusa tulda and evaluating its bioactivity. The extraction of IAA was performed in organic solvent followed by sample evaporation and TLC with a mobile phase composed of chloroform, methanol and formic acid (77:22:1 v/v) in isocratic mode. The extract obtained from preparatory TLC was subjected to HPLC with acetic acid and methanol (75:25 v/v) as the mobile phase in isocratic mode at a flow rate of 0.8 ml/min and operation pressure of 54 MPa at 30°C, and detection was monitored at 280 nm. Bioassay of the extracted IAA was carried out in Abelmoschus esculentus seedlings. The similar Rf value (0.412) of the extract during TLC analysis and similar peak of HPLC chromatogram with retention time 28.71 min to that of standard IAA indicated the presence of IAA in B. tulda seedling extract. The extracted IAA was quantified to be 10.28 µg/ml. In bioassay experiment, the extracted IAA significantly enhanced root length, root fresh weight, root dry weight, shoot length, shoot fresh weight, shoot dry weight and significant increase of total chlorophyll and protein in A. esculentus leaves. Therefore, B. tulda seedlings could be a potential source of IAA, and it can be utilized for production of bio-fertilizer at a commercial scale.

Key words:  Abelmoschus esculentus, Bamboo, High performance liquid chromatography, indole-3 acetic acid.