Abstract

SANCHEZ, Vladimir  and  REBOLLEDO, Oscar. Trichoderma species in soil cultivated with Agave tequilana in Los Altos South region, Jalisco and assessment of their antagonistic capacity against Thielaviopsis paradoxa. Rev. Mex. Mic [online]. 2010, vol.32, pp.11-18. ISSN 0187-3180.

A survey was conducted to determine the species of Trichoderma from the soil of commercial plantations of tequila agave (Agave tequilana) in the Los Altos Sur region located in Jalisco State, Mexico in order to study them as biocontrol agents against one of the plant pathogens that attack the tequila agave. Sixty four cultures of Trichoderma were identified morphologically and some of them by DNA sequencing analyses of the internal transcribed space (ITS), translation elongation factor 1 alpha (tef1), actin (act), and calmodulin (cal). Morphologically, 60 isolates (93.7%) were identified as T. longibrachiatum and ITS sequence data for 25 of these cultures confirmed their identity. Three cultures (4.6%) were identified as T. harzianum and DNA sequences of ITS, tef1, act and cal confirmed the result. One culture (1.5%) was identified morphologically and by ITS sequence data as T. reesei. Antagonism against Thielaviopsis paradoxa was evaluated for several isolates of each species of Trichoderma. Isolates of T. longibrachiatum, T. viridescens and T. reesei produced significantly higher inhibition against Th. paradoxa than T. harzianum.

Keywords : molecular identification; morphology; taxonomy; biological control.