|Jefferson, P - AGRIC & AGRI-FOOD CANADA|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 23, 1999
Publication Date: N/A
Interpretive Summary: Russian wildrye is a drought-tolerant, cool-season forage grass that is indigenous to central Asia but well adapted to temperate, semiarid regions of North America. This grass maintains relatively high levels of digestibility and protein with advancing maturity and has been used to extend the grazing season beyond what is provided by our native grasslands. Numerous collections of Russian wildrye have been introduced to North America in recent years, but this new genetic stock has not been adequately characterized to enable its efficient use in plant breeding programs. Sixty-six populations and three cultivars of Russian wildrye were tested at three diverse test sites located in Utah, North Dakota, and Saskatchewan. We found that forage and seed yields had some consistency across these locations, but that testing at each of the three sites was necessary to identify the highest yielding populations for each location. Populations collected within the same geographic area tended to have similar combinations of plant traits, but distinctly different populations were sometimes found within the same general collection area. These data emphasize the importance of collecting Russian wildrye at diverse sites within a general geographic area whenever possible and of field testing these collections at diverse sites to determine the extent of their adaptation.
Technical Abstract: Russian wildrye [Psathyrostachys juncea (Fischer) Nevski] accessions in the U.S. National Plant Germplasm System have not been adequately characterized for agronomic and morphological traits. This study ascertains consistency of performance of 65 Russian wildrye accessions and four cultivars in field tests at Logan, UT; Mandan, ND; and Swift Current, Saskatchewan, Canada. A second objective was to characterize both the diversity and similarity among these accessions using cluster analysis. Although location X accession interaction effects for dry- matter yield were not statistically significant (P>0.05), only five of the 69 entries were ranked in the top quartile at all three locations and only seven were ranked in bottom quartile. Most other agronomic traits had significant (P=0.05) location X accession interactions. Thus, testing at each location was necessary to identify accessions that were best suited to a specific location. The 69 entries were grouped into 9 clusters based on multivariate analysis of 17 classification variables. Accessions from a defined geographic area tended to cluster, but some accessions from a localized area were spread among several clusters. This emphasizes the value of sampling diverse collection sites within a general geographic area whenever possible.