Plant & Animal Genomes XVIII Conference

January 9-13, 2010
Town & Country Convention Center
San Diego, CA

Hybridization Between Native And Introduced Rubus In California And The Pacific Northwest

Lindsay V Clark , Marie Jasieniuk

  Department of Plant Sciences, Robbins Hall, Mail Stop 4, University of California - Davis, One Shields Avenue, Davis, CA 95616

Hybridization between native and introduced species is often detrimental to native ecosystems, in that it can facilitate the evolution of new invasive species, cause outbreeding depression in native species, and drive native species to extinction by genetic swamping. Such hybridization seems especially likely to occur in Rubus of California and the Pacific Northwest, given the presence of multiple naturalized introduced species, native species, and cultivated varieties; the tendency of the genus towards hybridization; and the existence of many invasive Rubus species worldwide. We have sampled total of approximately 550 Rubus individuals of eight native and naturalized species and two cultivars across 32 sites in California, Oregon, and Washington. Using microsatellites, AFLPs, and chloroplast markers, we have identified hybridization events between at least four unique pairs of species, three of which involved both native and introduced parent species. We did not find any cases in which hybridization appeared to have progressed beyond the F1, possibly due to ploidy differences between parent species and the primarily apomictic reproductive mode of the introduced species. Future experiments will assess the vigor and invasiveness of artificial hybrids of these types, as well as determine whether these hybrid types reproduce sexually or through apomixis.