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ARS Home » Midwest Area » Madison, Wisconsin » U.S. Dairy Forage Research Center » Dairy Forage Research » Research » Publications at this Location » Publication #314396
Title: Switchgrass germplasm resources

Author
item Casler, Michael
item Vogel, Kenneth
item Harrison, Melanie

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/30/2015
Publication Date: 11/1/2015
Publication URL: http://handle.nal.usda.gov/10113/62837
Citation: Casler, M.D., Vogel, K.P., Harrison, M.L. 2015. Switchgrass germplasm resources. Crop Science. 55:2463-2478.

Interpretive Summary: Switchgrass is an important native grass and dominant member of the tallgrass prairie ecosystem. It is used for conservation, restoration, livestock feed production, and bioenergy feedstock production. This paper describes the fundamental environmental principles and characteristics that cause switchgrass to be variable across its range from the Rocky Mountains to the Atlantic Seaboard. The paper describes origins and sources of plant material that have been collected and highlights areas that still need to be collected for inclusion in the national gene bank. The paper provides a comprehensive resource for anyone interested in switchgrass to find either commercial varieties or wild plant material to fulfill any one of many needs and uses.

Technical Abstract: Switchgrass (Panicum virgatum L.) is an important native grass and dominant member of the tallgrass prairie ecosystem. It is used for conservation, restoration, livestock feed production, and bioenergy feedstock production. Upland and lowland ecotypes represent the most important polymorphism in switchgrass, with distinct but overlapping geographic distributions. Variation in ploidy exists within both ecotypes, with 2n=4x=36 the dominant ploidy in the lowland ecotype and 2n=8x=72 the dominant ploidy in the upland ecotype. Ploidy is a strong barrier to gene flow, but ecotype is a weak barrier, with up to 10% of random individuals demonstrating some evidence for upland-lowland hybridization in their ancestry. Latitudinal and, to a lesser extent, longitudinal differentiation exists within each ecotype, such that most wild populations and cultivars are not well adapted more than one hardiness zone from their place of origin. Plant breeding can alter this relationship by creating populations that improved cold tolerance, for example, increasing the adaptation range of an individual cultivar. The USDA National Plant Germplasm System maintains the national switchgrass collection, which is available for research and breeding purposes.