Abstract
The overall objective is to evaluate the possibility of biological control of phytophagous insects on willows by means of mycorrhizal inoculation. Willow (Salix spp.) grown on agricultural land is increasing in importance as a potential source of renewable energy, but willow growth is often reduced by a number of pests and diseases. The willow model system has several advantages to study the relationships between root mycorrhizal colonisation and leaf herbivore resistance, because willows are easy to propagate vegetatively, have high levels of defensive compounds and are mycorrhizal. We intend to analyse the indicated relationships from a plant resource economy perspective and particular attention will be paid to the role of phenolics, which are involved both in the root mycorrhizal colonisation and insect defence mechanisms of plants. The following two major hypotheses will be addressed, specifically for the willow system: 1) genetically determined differences in mycorrhizal colonisation are inversely correlated with plant resistance to insect herbivory; 2) irrigation/inoculation with appropriate mycorrhizal strains increases mycorrhizal colonisation phenotypically and goes then along with a stimulation of plant resistance to herbivory. The hypotheses will be tested by means of one field study and two laboratory experiments. The major research within the project will be performed by a PhD student in collaboration with experts in plant ecology, mycology and entomology.
Sweden