Redundancy analysis of the influence of metal content and other edaphic parameters on the coexsistence of Trichoderma species

Abstract

The growth requirements of Trichoderma fungi that are wide spread saprotrophic soil micro-organisms, are quite similar, therefore it is essential to define the environmental factor(s) along which they divide the available ecological niches. For this reason, we determined chemical and physical properties of 24 soil samples from different localities of Hungary, the presence of Trichoderma species and the relationships between two groups of data were analyzed with different statistical methods. The coexistence of 13 identified Trichoderma spp. proved to be a general phenomenon, which provided a good opportunity to explore the dividing environmental factors. Only redundancy analysis gave a reasonable model from 26 abiotic soil parameters. However, the number of variables was two times higher than that of species, thus the model was built in step-by-step process during which the explanation power of parameters was assessed with Monte Carlo permutation test. The best possible model of 13 soil properties explained 66.19 % of variance in the occurrence of Trichoderma species. Their positions in the triplots showed the separation of their niches along some of the investigated abiotic environmental variables. The available Zn-content had the highest explaining power however the in vitro zinc tolerance test did not justify its importance. © 2006, Penkala Bt.