SELECTION OF Trichoderma spp. STRAINS EFFICIENT ON BIOCONTROL OF PHYTOPATHOGENIC FUNGI AND PLANT PRODUCTIVITY INCREASE.

VF CONSOLO, CI MONACO CA CORDO AND GL SALERNO

Mar del Plata

Congreso; VIII Congreso de Microbiologia General; 2012

SELECTION OF Trichoderma spp. STRAINS EFFICIENT ON BIOCONTROL OF PHYTOPATHOGENIC FUNGI AND PLANT PRODUCTIVITY INCREASE. Consolo V. F.1; Mónaco C.M.2; Cordo C.2  y Salerno GL1 1CEBB-CIB FIBA, Vieytes 3103, 7600 Mar del Plata, Argentina 2CIDEFI, Facultad de Cs Agrarias y Forestales UNLP. 60 y 119, 1900, La Plata, Argentina Email: faconsolo@fiba.org.ar Trichoderma fungi represent a dominant group of soil microflora, and large numbers of strains have been recognized as biocontrol agents. These fungi are opportunistic, avirulent plant symbionts, and acts as antagonists of many phytopathogenic fungi, thus protecting plants from disease. The overall objective of our project is to increase the sustainable production of wheat and rice in Argentina through the study and development of biological products based on Trichoderma spp. In this work, we developed activities involving the comprehensive characterization of Trichoderma spp isolates collected from different sites in Buenos Aires Province. Molecular markers were applied to analyze the genetic variability of isolates. We also carried out the determination of morphological, physiological and biochemical features. We evaluated the activity of hydrolytic enzymes as indicators of strains inhibitory capacity against various fungal pathogens. It was determined that three isolates showed significant enzymatic activity that corresponded with its large inhibitory activity (85%) against five species of phytopathogenic fungi. Strains of Trichoderma spp. was evaluated about their ability to promote plant growth by analyzing the ability of solubilizing soil phosphorus, as well as determined its role in increasing plant biomass in rice plants. It was concluded that 60% of strains tested at different times of growth of the fungus were able to increase the soluble phosphorus concentration in the culture medium; these results were consistent with a reduction in pH in the culture medium. Seven isolates were selected for the ability to colonize the roots of rice seedlings as well as its ability to increase plant biomass. Rice plants of Don Juan and El Paso 144 varieties were evaluated. We observed that that four of the seven isolates tested increased the biomass of seedlings between 20 and 30%. The evaluated parameters are useful in selecting Trichoderma spp. Isolates candidates to be formulated as biological control agents. This research was supported by UNMDP EXA 553/2011, CONICET and FIBA.