Abstract

DUARTE-LEAL, Yanisia; LAMZ-PIEDRA, Alexis  and  MARTINEZ-COCA, Benedicto. In vitro antagonism of Trichoderma asperellum Samuels, Lieckfeldt & Nirenberg isolates against Sclerotium rolfsii Sacc.. Rev. Protección Veg. [online]. 2017, vol.32, n.3, pp.00-00. ISSN 1010-2752.

The objective of this work was to determine the modes of action (antibiosis, competition for space and nutrients, and mycoparasitism) of ten strains of T. asperellum Samuels, Lieckfeldt & Nirenberg (Ta.) against two isolates of S. rolfsii Sacc. (Scl) isolated from common bean (Phaseolus vulgaris L.). In vitro antagonism was assessed by the dual culture method, through which the different modes of action were determined. Most strains of Ta. were located in grade 2 of the Bell scale, except Ta. 17, which showed grade 5. The metabolites produced by strains Ta. 28, Ta. 13, and Ta. 90 showed the highest inhibitory effect on Scl 5 growth, whereas those produced by the strains Ta. 13, Ta. 79, Ta. 28, Ta. 75, Ta. 85, and Ta .90 did on Scl 6. Greater competition for nutrients was observed with the strain Ta.28. Mycoparasitism results showed the best strain was Ta. 90 with three types of hyphal interactions between the two fungi, followed by Ta. 13 and Ta. 56 with three and two types of interactions, respectively. According to the modes of action of the strains Ta. 13, Ta. 28, and Ta. 90, they can be evaluated as possible candidates for active ingredients of biopesticides for the control of S. rolfsii in the bean crop.

Keywords : biological control; hyphal interactions; soil pathogen.

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