Landscape patterns of phenotypic variation and population structuring in a selfing grass, Elymus glaucus (blue wildrye)

Source-related phenotypic variance was investigated in a common garden study of populations of Elymus glaucus Buckley (blue wildrye) from the Blue Mountain Ecological Province of northeastern Oregon and adjoining Washington. The primary objective of this study was to assess geographic patterns of potentially adaptive differentiation in this self-fertile allotetraploid grass, and use this information to develop a framework for guiding seed movement and preserving adaptive patterns of genetic variation in ongoing restoration work. Progeny of 188 families were grown for 3 years under two moisture treatments and measured for a wide range of traits involving growth, morphology, fecundity, and phenology. Variation among seed sources was analyzed in relation to physiographic and climatic trends, and to various spatial stratifications such as ecoregions, watersheds, edaphic classifications, etc. Principal component (PC) analysis extracted four primary PCs that together accounted for 67% of the variance in measured traits. Regression and cluster analyses revealed predominantly ecotypic or stepped-clinal distribution of genetic variation. Three distinct geographic groups of locations accounted for over 84% of the variation in PC-1 and PC-2 scores; group differences were best described by longitude and ecoregion. Clinal variation in PC-3 and PC-4 scores was present in the largest geographic group. Four geographic subdivisions were proposed for delimiting E. glaucus seed transfer in the Blue Mountains.Key words: Elymus glaucus, morphological variation, local adaptation, seed transfer, seed zones, polyploid.

Isozyme variation and its environmental correlates in Elymus glaucus from the California Floristic Province

Genetic variation in the self-fertile, allotetraploid grass Elymus glaucus Buckley was assessed using isozymes in 133 populations from southwestern Oregon and from the San Francisco Bay area and central Sierra Nevada mountains in California. Elymus glaucus was highly (98.5%) homozygous but also highly variable; 77% of loci were polymorphic, and the mean number of alleles per locus was 2.96. Populations were highly differentiated, with 40% of variation among populations. Geographic and genetic distances among populations were not correlated, except that populations collected within 5 km were generally more similar than average. Genetic distance among populations could not be predicted from geographic distance, geographic location, foliage pubescence, serpentine substrate, or habitat moisture. However, two genetic clusters, associated with elevation, did emerge. The taxonomic status of Elymus glaucus ssp. jepsonii (Burtt Davy) Gould, based on leaf pubescence, was not supported.Key words: Elymus glaucus, isozyme, genetic variation, Poaceae, polyploid, seed transfer.

ELYMANA SULPHURELLA (ZETTERSTEDT): BIOLOGY, TAXONOMY, AND RELATIVES IN NORTH AMERICA (RHYNCHOTA: HOMOPTERA: CICADELLIDAE)

Elymana sulphurella (Zetterstedt) is confirmed as an introduced European species, and is distinguished from its relatives in the New World, including 2 new species E. circius (British Columbia to Saskatchewan) and E. pacifica Hamilton (British Columbia). Elymana acrita DeLong 1936 is synonymized with E. acuma DeLong 1936, and E. caduca DeLong 1936 is synonymized with E. inornata (Van Duzee 1892). A key to the New World species is presented. A method of rearing E. sulphurella in a controlled environment is described. Of 11 plant species tested as food hosts, Agrostis gigantea Roth., Elymus glaucus Buckl., Festuca arundinacea Schreb., F. elatior L., F. rubra L., and Phleum pratense L. were suitable for nymphs and adults, Lolium perenne L. for nymphs, and Alopecurus pratensis L., Bromus inermis Leyss., and Dactylis glomerata L. for adults. Digitaria sanguinalis (L.) Scop. and Echinochloa crus-galli (L.) Beauv. were unsuitable for both stages. Ten of 11 plant species tested as oviposition hosts yielded nymphs but the numbers varied widely. Leaf blades were preferred over sheaths as oviposition sites and most eggs were laid in the lower two-thirds of the leaf. Eggs appeared to be in diapause when laid and required several months to hatch if held at room temperature. Cold treatment of such eggs decreased the minimum hatching time and reduced the period over which hatching occurred. The mean developmental period of females was 24.9 days and males 23.5 days. The mean longevity of mated females (83.2 days) was significantly (P = 0.05) longer than that of males (62.1 days).