Effect of genetic relatedness on volatile communication of sagebrush (Artemisia tridentata)

Sagebrush (Artemisia tridentata) uses volatile cues to induce systemic resistance to herbivory within and between plants (so-called volatile communication). Previous study revealed that the volatile components varied among individuals and that sagebrush suffered less damage when it received volatiles from clonally potted genetically identical branches than when it received volatiles from genetically different potted branches. In this study, we investigated whether there are genetic relationships among individuals growing within 60 cm where volatile communication occurs under natural condition, and whether volatile components are influenced by genetic relationships. By using genetic analysis involving microsatellite markers, we found that genetically identical ramets which were thought to be clonally propagated and genetically closely related ramets were growing near to each other. In addition, volatile components were similar among genetically identical or closely related ramets. Our results imply that genetic relatedness and volatile similarities may influence the strength of induced resistance of ramets that received volatiles.