Community genetics of poplar and oak as a keystone species for insects and mycorrhiza

Community genetics aims to understand how genetic variation within and among populations of host species affects the composition of ass ociated organisms (insects, fungi, and other organisms) interacting with the host species. Community genetics has been stimulated by pioneering work on poplars (Populus spp.), linking their genotypic and phenotypic variation to variation in associated communities. The future of community genetics will be to identify the genes that underlie the traits of hosts that affect the presence or abundance of associated organisms. This can be done by e.g. quantitative trait analysis (QTL) mapping and genome-wide association studies (GWAS). I will present some results from the Evoltree projects on community genetics in poplar and oak. In one of the experiments the F2 offspring of a hybrid poplar (Populus trichocarpa x P. deltoides) cross were assessed for seven categories of insect leaf damage at two time points, June and August. The seven forms of leaf damage were used as a proxy for seven functional groups of insect species. Significant variation in insect association was found among the hybrid offspring, including transgressive segregation of susceptibility to damage. QTL analyses identified 14 genomic regions across 9 linkage groups that correlated with specific insect association. The results provide insight into the genetic components involved in insect community structure in a fast-growing forest tree. DeWoody J et al. (2013) Insight into the genetic components of community genetics: QTL mapping of insect association in a fast-growing forest tree. PLoS ONE 8: e79925. Gugerli F et al. (2013) Community genetics in the time of next generation molecular technologies. Molecular Ecology 22: 3198–3207.