Do Invasive Tamarisk Trees Form Symbioses with Root-Associated Fungi?
 
Abril Belgara-Andrew1, Lisa M. Markovchick2, Julia Hull3, Kevin Hutline4, Randy Long5, Catherine A. Gehring 6, & Thomas G. Whitham7
 
1Department of Physics and Environmental Science, St. Mary’s University, San Antonio, TX 78228, U.S.A. Abelgaraandrew@mail.stmarytx.edu.
2 Department of Biological Sciences and Merriam-Powell Center for Environmental Research, Northern Arizona University, Flagstaff, AZ 86011, U.S.A.;  Lisa_Markovchick@nau.edu.
3 Department of Biological Sciences and Merriam-Powell Center for Environmental Research, Northern Arizona University, Flagstaff, AZ 86011, U.S.A.; Julia.b.hull@gmail.com
4Desert Botanical Garden, Phoenix, AZ 85008, U.S.A.; Khultine@dbg.org
5Desert Botanical Garden, Phoenix, AZ 85008, U.S.A.; Rlong@ucsb.edu
6 Department of Biological Sciences and Merriam-Powell Center for Environmental Research, Northern Arizona University, Flagstaff, AZ 86011, U.S.A.; Catherine.Gehring@nau.edu
7 Department of Biological Sciences and Merriam-Powell Center for Environmental Research, Northern Arizona University, Flagstaff, AZ 86011, U.S.A.; Thomas.Whitham@nau.edu
 
 
Like other types of mycorrhizal fungi, arbuscular mycorrhizal fungi (AMF) form mutualistic relationships with plants. AMF are the most common, associating with approximately 80% of all plant species. Tamarisk (Tamarix spp.) are invasive to North America. Tamarisk form relationships with AMF in their native range; however, there is little to no evidence of AMF association in their invasive range. Rather, tamarisk do host another type of root-associated fungi, dark septate endophytes (DSE), whose effect on their host plant is less clear than with AMF. In this study, we analyzed roots from several populations of tamarisk grown in a common garden in Arizona, and tamarisk roots from a naturalized population, to evaluate whether symbioses with root-associated fungi were present. We found no conclusive evidence of AMF but observed DSE in roots from all populations. Rates of DSE colonization were similar among populations but decline significantly with increasing soil depth. Mean temperature did not seem to affect the amount of DSE found in populations suggesting that DSE is not adapted locally or that tamarisk is adapted to the DSE.