The Potentiality of Forest Litter Fungi as IAA (Indole-3-acetic acid) Producer

Abstract

Many industrial forest in Indonesia are replanted under intensive silviculture program. This program includes utilizing of soil microorganism for promoting better plant growth. Preliminary study was done on the exploration of forest litter fungi that are able to produce IAA. Six thermotolerant fungi (Aspergillus sp B.10, Aspergillus sp 20.2, Penicillium sp 4.2, Aspergillus sp 9.2, Penicillium sp 1.2 and Trichoderma sp B.2) have been isolated from forest litter. All isolates produced IAA with various concentration, ranges from 15.56 ppm to 76.81 ppm. Two isolates (Penicillium sp 1.2 and Trichoderma sp B.2) which produced the high IAA contents were further examined. Bioassay of 10-2 ppm, 10-4 ppm and 10-6 ppm of crude extract IAA using mung bean (Vigna radiata) seedling indicated that the extract only significantly effected on the number of lateral root. Filtrate from those isolates induced lateral root formation more than those of IAA standard on the same concentration.