Variation in the ability to form ectomycorrhizas in the F1 progeny of an interspecific poplar (Populus spp.) cross

The aim of this study was to determine the existence of a genetic basis for the ability to form ectomycorrhiza on a model angiosperm tree (Populus, poplar). Parental clones and 18 progeny from a controlled interspecific cross between Populus deltoides and Populus trichocarpa were grown in a glasshouse and inoculated with mycelium of the ectomycorrhizal fungus Laccaria bicolor. Three months after inoculation, the percentage of mycorrhizal root tips was determined for each inoculated plant. The data indicate variability in the ability to form ectomycorrhizas among the Fl progeny, including individual progeny which are different to either parent. This suggests a genetic basis for mycorrhiza formation.