NOVAK, STEPHEN J.* and ANGELA Y. WELFLEY. Department of Biology, Boise State University, Boise, ID 83725-1515. - Allozyme variation within and among populations of the introduced plant Poa bulbosa (Poaceae).
Poa bulbosa L. is a small perennial bunchgrass that possesses a
wide distribution throughout Western Europe and the Mediterranean.
This grass has been introduced into North America and now occurs
throughout much of the western United States, particularly in the
Intermountain West. In its native range, P. bulbosa reproduces
through both sexual and asexual means; however, in its introduced
range in the Intermountain West it primarily reproduces clonally
through the production of bulbils. Also, high chromosome numbers are
frequently reported, suggesting that this grass is a polyploid. Using
enzyme electrophoresis, we analyzed 10 populations of P.
bulbosa from Idaho, Oregon and Washington by staining for 14
enzymes that were coded for by 19 putative loci. Our results indicate
that P. bulbosa contains higher levels of genetic variation
than would be expected for an introduced clonal plant species: 27.9%
of loci are polymorphic per population, with an average of 1.54
alleles per locus, and a mean observed heterozygosity of 0.202. The
high levels of heterozygosity observed for this grass are consistent
with previous reports for autopolyploid plant species. Finally, the
complex distribution of multilocus genotypes exhibited by P.
bulbosa suggests the possibility of multiple introductions of this
species into its new range.
Key words: allozyme variation, clonal reproduction, introduced plant, multilocus genotypes, Poa bulbosa, Poaceae