In vitro selection of Strains of Trichoderma spp.with phosphate solubilizing and indole acetic acid producing capacities
By: Dorcas Zúñiga-Silgado , León Darío Vélez Vargas
Key Words: Biosolubilization of phosphorous, Trichoderma sp., Biosolubilization, bioacidulation, IAA production.
Int. J. Biosci. 8(5), 153-174, May 2016.
Trichoderma spp., in addition to having biocontrolling effects on pathogens, exhibit phosphodissolvent and IAA
production capacities; Our hypothesis suggests that the efficiency of some strains of Trichoderma in
phosphodissolving and producing IAA is a function of the type of strain, the incubation time, and the
concentration of specific precursors or inductors of hormones present in the system. The central aim of this investigation had as an objective the in vitro selection of strains of Trichoderma spp. isolated from the rhizosphere of beans and corn with phosphate solubilizing and indole acetic acid (IAA) producing capacities. Nine (9) different strains of Trichoderma were isolated and selected from the rhizosphere and rhizoplane of beans and corn. In order to evaluate their phosphodissolvent capacities, these strains were cultivated in three solid media and three liquid media with and without Phosphoric Rock (PR). The relative efficiency of solubilization (RSE), bioacidulation, and hosphodissolution was then determined. IAA production capacity was evaluated as a function of strain, time, and concentration of L-Tryptophan. For this, 9 strains of phosphodissolvent Trichoderma were tested, and 4 turned out to be IAA producers.There were highly significant differences (P ≤ 0.01) in phosphodissolvent capacity and IAA production in relation to the variables studied and the strains evaluated. It is an important mechanism of adaptation to the ecological success of both plants and microorganisms which in turn represents a valuable genebank for agro-ecological and agrobiotechnological applications.