The influence of host genotype and monoterpene profile on the ectomycorrhizal communities of Scots pine trees
The aim of this thesis was to investigate whether the genotype/chemotype of a host pine tree affects the structure/composition of the EcM community associated with its roots. The first step was the development of a method for identification of the host tree from EcM root tip tissue: pine specific microsatellite loci within EcM root tip tissues were targeted to produce “fingerprints” specific to individual trees. This microsatellite fingerprinting approach was applied in the field to describe the EcM communities on 5 individual trees in a native Scots pine woodland. 93% of mycorrhizas beneath the crown projection of a tree belonged to that tree, although mycorrhizas were found upto 18 m from the stem. 8-16 EcM fungi were recorded for each tree in the top 14 cm of the soil. No differences were observed between EcM communities on individual trees. The microsatellite fingerprinting approach was then used to test whether monoterpene chemotype (concentration of 3-carene) affects the EcM communities associated with individual trees. Monoterpene chemotypes did not have a selective effect on the EcM communities on individual trees or under canopies of contrasting chemotype. If the host monoterpene chemotype does have an effect on EcM communities, it is likely to involve the overall monoterpene profile, rather than the concentration of an individual monoterpene. EcM community composition was also found to vary spatially. A microcosm study investigated whether the monoterpene chemotype affects early fungal colonisation of litter.