Clay, Danielle , Smith, James , Novak, Stephen , Serpe, Marcelo .
Homoploid hybrid speciation in a rare endemic Castilleja from Idaho.
Interspecific hybridization has played a pivotal role driving both extinctions and speciation events within angiosperms. The combination of interspecific hybridization and allopolyploidy has significantly contributed to the evolution of the genus Castilleja. The diploid Castilleja christii is a highly fertile rare endemic species, and widespread on 200 acres at the summit of Mt. Harrison, ID. We provide evidence for the homoploid hybrid speciation of Castilleja christii between congeneric diploids Castilleja miniata and C. linariifolia, using molecular and morphological analyses. Some individuals of Castilleja christii that were initially thought to be hybrids between C. christii and either C. miniata or C. linariifolia were found to be transgressive for several morphological traits based on ANOVA analyses and Cochran-Mantel-Haenszel test statistics. Using the single copy nuclear gene waxy, all Castilleja christii individuals were found to share the genomes of C. miniata and C. linariifolia. All individuals of Castilleja christii and C. linariifolia sampled from Mt. Harrison were identified as diploids using chromosome squashes. Most individuals of C. miniata were also diploid with the exception of one subpopulation that was octoploid. This study is the first to report homoploid hybrid speciation in the genus Castilleja, adding to the understanding of the complex evolutionary history in this group. Further, this research will assist land managers with conservation strategies that may contribute to the species protection of Castilleja christii, which to date has not been explored scientifically.
Log in to add this item to your schedule
1 - Boise State University, Biological Sciences, 1910 University Drive, Boise, ID, 83725-1515, USA
Homoploid hybrid speciation
single copy nuclear gene
Presentation Type: Oral Paper:Papers for Sections
Location: Lindell A/Chase Park Plaza
Date: Wednesday, July 13th, 2011
Time: 2:00 PM