Are symbionts facilitating edaphic adaptation? Arbuscular mycorrhizal assemblages associated with serpentine and non-serpentine ecotypes of Collinsia sparsiflora

The extreme edaphic features of serpentine soils have selected for unique, locally adapted plant assemblages. Interactions with beneficial root symbionts may be involved in plant adaptation to serpentine soil. Arbuscular mycorrhizal fungi (AMF) are common root symbionts that can increase the plant hosts’ establishment and growth in stressful environments. However, little is known about this relationship for serpentine plants or the role plant-AMF interactions play in plant adaptation to serpentine. To address whether plant ecotypes require specific AMF taxa, I examined the AMF assemblages associated with populations of serpentine and non-serpentine ecotypes of California native plant Collinsia sparsiflora. Roots of C. sparsiflora were sampled from three serpentine and three non-serpentine sites in close proximity (75 m to 951 m between sites) at the McLaughlin Reserve in northern California. Root DNA was amplified with AMF specific primers NS31 and AM1, cloned, and sequenced. Preliminary results indicate that each plant ecotype associates with distinct AMF in the Glomeraceae. This information has important implications for conservation and restoration of serpentine plants. Collection and identification of key fungal components of serpentine ecosystems could dramatically improve success of restoration efforts.