Phosphate solubilization and phytohormone production by endophytic and rhizosphere Trichoderma isolates of guanandi (Calophyllum brasiliense Cambess)

This work aimed to isolate and evaluate the phosphate solubilization and phytohormone production abilities of endophytic and rhizosphere fungi belonging to the genus Trichoderma isolated from guanandi (Calophyllum brasiliense Cambess). From the guanandi collected from the field, 12 isolates obtained were grown in potato dextrose broth and supplemented with the phosphate sources, to test their capacity to solubilize phosphates. A strain of Trichoderma asperellum from a commercial inoculant was also used. One isolate was able to solubilize calcium phosphate, 12 solubilized iron phosphate and two solubilized aluminum phosphate. Only the rhizosphere isolates were able to synthesize indole acetic acid (IAA) and none of the rhizosphere or endophytic isolates produced cytokinin or gibberellin. There are Trichoderma isolates that can benefit plant development, both for their known antagonistic ability against phytopathogenic fungi and for their ability to provide phosphates and or to produce phytohormones. Key words: Trichoderma, inoculants, calcium, iron, aluminum, solubilization, plant growth promotion.