|Van Santen, E|
Submitted to: Molecular Breeding of Forage and Turf Conference
Publication Type: Book / Chapter
Publication Acceptance Date: 12/1/2007
Publication Date: 11/6/2008
Citation: Casler, M.D., Van Santen, E., Humphreys, M.W., Yamada, T., Tamura, K., Ellison, N.W., Jackson, R.D., Undersander, D.J., Gildersleeve, R., Opitz, C. 2008. Remnant Oak Savanna Acts as Refugium for Meadow Fescue Introduced During 19th Century Human Migrations in the USA. In: Yamada, T., editor. Molecular Breeding of Forage and Turf: The Proceedings of the 5th International Symposium on the Molecular Breeding of Forage and Turf. New York, NY: Springer. p. 91-101. Interpretive Summary: We have discovered a new potentially valuable forage grass on a farm in southwestern Wisconsin. Using several DNA markers, we have identified this grass as meadow fescue, a grass introduced from Europe or Asia in the late 19th century. We think that meadow fescue populations have survived in southwestern Wisconsin as intact pastures or as surviving plants in remnant oak savannas that were never plowed. These meadow fescue plants are highly persistent, palatable, and drought tolerant, providing germplasm that will be useful in developing new varieties to improve productivity and stability of pasture systems utilized by livestock producers.
Technical Abstract: In 1990, an unknown forage grass was discovered growing in the shade of a remnant oak savanna in southwestern Wisconsin. Over 12 years, the practice of feeding mature hay on winter pastures spread this grass onto over 500 ha via seedling recruitment. Analysis of amplified fragment length polymorphic (AFLP) markers on 561 plants, compared to a diverse sample of wild European collections of perennial ryegrass (Lolium perenne L.), Italian ryegrass (L. multiflorum Lam.), meadow fescue (Festuca prat-ensis Huds. = L. pratense (Huds.) Darbysh.), and tall fescue (F. arundina-cea Schreb.), identified a highly diverse population that was more closely allied with F. pratensis than the other species, based on genetic distances. Genomic in situ hybridization (GISH), using both Lolium- and Festuca-specific probes, led to effective hybridizations by only the Festuca-specific probes and gave indications of close homology to the F. pratensis genome. Similarly, genetic distance analysis using PCR-based Lolium expressed se-quence tag (EST) markers on a subset of genotypes, compared to the four control species, clearly identified F. pratensis as the closest relative. Se-quence analysis of the trnL intron of cpDNA distinguished the unknown plants from F. arundinacea, but not from Lolium. Additional survey work has identified this grass on 12 other farms within an area of about 20,000 ha. Soil samples accompanying plant samples indicated no seed banks and most farm records indicate no commercially introduced seeds during the 20th century. We hypothesize that seeds of meadow fescue may have ar-rived with some of the earliest European immigrants to Wisconsin and spread along the historic Military Ridge Trail, a network of frontier U.S. Army forts connected by a major thoroughfare.