Russian-olive (Elaeagnus angustifolia) genetic diversity in the western United States and implications for biological control

Authors: Gaskin, John; ANDRES, JOSE - Cornell University; BOGDANOWICZ, STEVEN - Cornell University; GUILBAULT, KIMBERLY - Colorado State University; HUFBAUER, RUTH - Colorado State University; SCHAFFNER, URS - Commonwealth Agricultural Bureau International (CABI) - Switzerland; WEYL, PHILIP - Commonwealth Agricultural Bureau International (CABI) - Switzerland; Williams, Livy

Submitted to: Invasive Plant Science and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/13/2019
Publication Date: 4/17/2019
Citation: Gaskin, J.F., Andres, J.A., Bogdanowicz, S.M., Guilbault, K.R., Hufbauer, R.A., Schaffner, U., Weyl, P., Williams III, L.H. 2019. Russian-olive (Elaeagnus angustifolia) genetic diversity in the western United States and implications for biological control. Invasive Plant Science and Management. https://doi.org/10.1017/inp.2019.16.
DOI: https://doi.org/10.1017/inp.2019.16

Interpretive Summary: Plant invasions can be genetically diverse, and that diversity can make it difficult to control these weeds, as some may react differently to chemical or biological control. We analyzed the population genetics of Russian olive; an important and common invading tree found in many western USA riparian areas. We found three genotype clusters in the 460 plants from 46 locations in the western USA. We found high levels of genetic diversity in the sampled locations. Our native range sampling was limited and we did not find close a genetic match for the most common genotypes. We did not find that different areas of the USA invasion had genetically different plants, but we did identify invasion locations that had the most diversity and suggest these as choices for initial biological control release monitoring. Trees from each genetic cluster, which coarsely represent the range of genetic diversity found in the invasion, are now are included in classical biological control tests to make sure that potential insect agents will be effective on all of the invasion.

Technical Abstract: Invasions can be genetically diverse, and that diversity may have implications for invasion management in terms of resistance or tolerance to control methods. We analyzed the population genetics of Russian olive; an important and common invading tree found in many western USA riparian areas. We found three cpDNA haplotypes, and using 11 microsatellite loci, identified three genotype clusters in the 460 plants from 46 locations in the western USA. We found high levels of polymorphism in the microsatellites and high observed and expected genetic diversity in the sampled locations. Our native range sampling was limited and we did not find close a genetic match for the most common cpDNA invasive haplotype, nor a strong confirmation of origin for the most common microsatellite genotype cluster. We did not find geographic population structure (isolation by distance) across the USA invasion, but we did identify invasion locations that had the most diversity and suggest these as choices for initial biological control release monitoring. Trees from each genetic cluster, which coarsely represent the range of genetic diversity found in the invasion, are now are included in potential classical biological control agent efficacy testing.