ABSTRACT
Exploring the in vitro bioefficacy of Trichoderma spp. against a fungal complex associated with chickpea wilt

Maria B. Contreras-Soto1, Kamila C. Correia2, Elizabeth Garcia-Leon3, Guadalupe A. Mora-Romero4, Milagros Ramirez-Soto5, Juan M. Tovar-Pedraza1, and Carlos I. Cota-Barreras5*
 
In Mexico, chickpea (Cicer arietinum L.) crop production is extensively limited and reduced by a disease known as wilt, caused by a complex of soil-borne plant pathogenic fungi. The objective of this study was to evaluate the antagonistic capacity of 31 isolates of Trichoderma spp. against the fungi Macrophomina phaseolina, Agroathelia rolfsii, Rhizoctonia solani, Neocosmospora falciformis, Fusarium languescens, F. nirenbergiae, and F. verticillioides. Trichoderma spp. isolates were obtained from rhizospheric soil and chickpea roots collected in the municipalities of Angostura and Salvador Alvarado, in Sinaloa, Mexico. Dual confrontations between the pathogen isolates and antagonistic agents were evaluated on PDA culture medium, using a completely randomized two-factor experimental design with three replicates. The recorded variable was the percentage of inhibition of radial mycelial growth. Of the 31 Trichoderma isolates evaluated, 22 induced > 55% inhibition of the plant pathogens; meanwhile, 7 Trichoderma isolates showed the highest antagonistic effect on each of the plant pathogens, causing > 59% inhibition. These 7 Trichoderma isolates were identified through multilocus phylogenetic analysis using internal transcribed spacer (ITS), EF-1α, and rpb2 sequences, distinguishing 5 isolates as T. afroharzianum and 2 isolates as T. afarasin. These Trichoderma spp. isolates represent a biological control alternative against the complex of fungi causing chickpea wilt in Sinaloa.
Keywords: Biological control, Cicer arietinum, Trichoderma afarasin, Trichoderma afroharzianum, phylogeny.
1Centro de Investigacion en Alimentacion y Desarrollo, Coordinacion Regional, Culiacan, 80110, Sinaloa, Mexico.
2Universidade Federal do Cariri, Centro de Ciencias Agrarias e da Biodiversidade, Crato, 63.133-610, Ceara, Brasil.
3Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias (INIFAP), Campo Experimental Valle del Fuerte, Sinaloa, Mexico.
4Universidad Autonoma de Occidente, Unidad Regional Los Mochis, Unidad de Investigacion en Ambiente y Salud, Los Mochis, 81223, Sinaloa, Mexico.
5Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias (INIFAP), Campo Experimental Valle de Culiacan, Sinaloa, Mexico.
*Corresponding author (carlosi.cotab@gmail.com).