Mycorrhizal colonization by Tuber aestivum has a negative effect on the vitality of oak and hazel seedlings

Abstract

Ectomycorrhizal fungi have a great impact on the ecosystem in boreal and temperate regions, and it has commercial, silvicultural and crop importance as well. The summer truffle (Tuber aestivum), a common mycorrhizal partner of several trees, is a valuable ectomycorrhizal fungus since its fruit bodies (ascomata) are a popular and expensive product on the global markets. To understand the physiology and ecology of a natural forest or a plantation, the participants and relationships between them should be examined. Hence, the maximal quantum efficiency of photosystem II centers, that is vitality of half a year old oak (Quercus robur) and hazel (Corylus avellana) seedlings inoculated with summer truffle was measured. The relation between the vitality of the plants and the rate of colonization of the fungus was examined applying single and multiple linear regressions. In the case of the oak seedlings contamination of Scleroderma spp. morphotype colonization was observed. Negative relationship between rate of colonization and the vitality was detected in the case of hazel seedling and non-contaminated oak seedlings. Multiple linear regression analysis revealed that there is no effect of truffle and contaminant fungi together, but alone the truffle has a negative impact. Consequently, the Scleroderma ectomycorrhiza seemed to have a balancing effect on the negative impact of summer truffle.