Friday, August 8, 2008

PS 79-84: Genetic and phenotypic diversity of remnant invaded native grass after two generations

Karin E. Bergum1, Ann L. Hild1, Franklin P. Bartlett1, and Brian A. Mealor2. (1) University of Wyoming, (2) The Nature Conservancy


Because invasive species may limit our ability to reclaim disturbed arid sites, restoration using competitive native species may limit return of exotics and enhance revegetation efforts.  To find competitive natives, we consider remnant grasses that persist within weed invasions as a seed source for revegetation.  This study examines the genetic diversity and phenotypic traits of seed from maternal lines of Sporobolus airoides derived from within and outside invasions of Acroptilon repens.  We use seed from two generations of greenhouse seed increase to compare the variability of potentially competitive traits.  AFLP markers characterize genetic variation in the maternal lineages and potential selection during greenhouse production of multiple generations.  Measurements on the following phenotypic traits have been collected:  germination rate, leaf number, tiller number, mean leaf length, and plant height.  Future measurements include inflorescence number and height, seed fecundity, and above-and below-ground biomass.   


Phenotypic variation between invaded and noninvaded populations are not found to be significant, but within the noninvaded population there is more variation among maternal lines than the invaded population.  The first generation of both populations demonstrates more competitive growth traits than the second generation.  Genetic diversity estimations of 36 maternal lines from two generations will determine if genetic drift or out-crossing has occured during greenhouse seed increasing.  Linking phenotypic variation to genetic diversity may aid in selection of competitive genotypes.  Increased phenotypic variability could be an attribute of high genetic variation or phenotypic plasticity.  Phenotypic consistency could imply low genetic diversity from selection.  Remnant natives with the ability to maintain genetic diversity and resiliency for multiple generations in a greenhouse could be vital for resistant restoration seedings and native plant production.