MORPHOLOGICAL AND PHYSIOLOGICAL DIVERSITY OF NATIVE STRAINS OF Trichoderma spp. IN SOILS WITH COCOA CULTIVATION IN MEXICO

Abstract

Objective: To study the morphological, microscopic and physiological diversity of native species of Trichoderma genus associated with soils with cocoa cultivation in Mexico.

Design / methodology / approximation: Colonies of Trichoderma spp. were isolated and characterized morphologically, microscopically and physiologically. from soil samples from six sites with different agronomic management: Organic Management, Conventional and No Management. A multivariate analysis (Analysis of main components and Analysis of hierarchical conglomerates) was carried out based on eight morphological characters of the colonies: shape, mycelium texture, obverse color, reverse color, central halo, number of concentric rings, type of sporulation and sporulation capacity; three microscopic characters: conidia shape and length / width relation of conidia and phialides.

Results: 30 strains with macroscopic characteristics of the genus Trichoderma were isolated and purified. The Principal Components Analysis showed that the first three components expressed 66.27% of the total variability in the 30 strains of Trichoderma spp., observing a wide distribution of the strains from the analysis of the evaluated characters. The analysis of hierarchical clusters determined eight groups divided into subgroups from the semiparcial correlation coefficient of 0.05.

Limitations of the study / implications: Trichoderma species show intraspecific variation that change with respect to the environmental conditions of the environment where they grow.

Findings / conclusions: The morphological, microscopic and physiological characterization shows a high variability expressed in different characters that demonstrate the high diversity and specificity of Trichoderma spp. in soils with cocoa cultivation in Mexico.