The influence of root symbionts and pathogens on different provenances of spruce

Regeneration plays the key role in the condition of a forest. By the choice of appropriate populations of the regeneration material and species it is possible to influence the future forest stand. In particular, different spruce populations show different resistance to red root rot. The aim of the research is to focus on this crucial step in forest planning aiming to learn about the physiological and genetic parameters of tree seedlings to be used in forest regeneration. It is likely that this phenomenon reflects differences in the functional compatibility of multiple symbiosis between forest trees and organisms in the rhizosphere, and that this is due to different genetics of the hosts, hormonal regulation, nutrient transfer and production or exudation of phytoalexines in the root systems. We are currently testing this hypothesis with a model system, consisting of different combinations of seedlings of spruce and chosen broadleaves, strains of symbionts and pathogens. The analysis include the anatomcal and potentially phenolic and nutrient, especially nitrogen analysis in different combinations of micro- and macro-symbionts. Special emphysis is also on studies of biodiversity of microsymbionts by application of molecular markers, which have not been used previopusly in Slovenia.