The extended consequences of genetic conductivity: mating distance affects community phenotypes in Norway spruce

Anthropogenic landscape level alterations such as habitat fragmentation and long distance translocation of genetic material are currently altering the genetic connectivity and structure of forest tree populations globally. As the susceptibility of individual trees to dependent organisms is often genetically determined, it is possible that these genetic changes may extend beyond individuals to affect associated communities. To test this, we examined how variation in crossing distance among the progeny of 18 controlled crosses of Norway spruce (Picea abies) populations occurring across central Sweden affected chemical defense, and subsequently, a small community of galling Adelges aphids infecting planted trees at two common garden trails. Although crossing distance did not influence growth, vitality nor reproduction in the studied population, it did influence the expression of one candidate defensive chemical compound, Apigenin, which was found in higher concentrations within outcrossed ...