ARS | Publication request: DIVERGENT BREEDING FOR TILLER IVDMD MODIFIED LEAF, SHEATH, AND STEM COMPOSITION OF SWITCHGRASS

Submitted to: Grassland International Congress Proceedings
Publication Type: Proceedings
Publication Acceptance Date: November 15, 2004
Publication Date: July 26, 2005
Citation: Vogel, K.P., Sarath, G., Mitchell, R. 2005. Divergent breeding for tiller ivdmd modified leaf, sheath, and stem composition of switchgrass. p.116. In F. P. O'Mara et al. (ed.) Proc. XX Int. Grassland Congress, Dublin, Ireland 26 June-2 July 2005. Wageningen, Academic Publishers, Wageningen, The Netherlands.

Interpretive Summary: Switchgrass is a cross-pollinated species that is native to the prairies of temperate North America. Breeding to improve its forage quality has been conducted using post-heading, whole plant in vitro dry matter digestibility (IVDMD) as the selection criterion. One breeding cycle for low IVDMD and three cycles for high IVDMD were completed in a switchgrass population adapted to the USA mid-latitudes. Sward trials demonstrated that whole plant IVDMD had been improved. The objective of this study was to determine the effect of breeding for tiller IVDMD on leaf, sheath, and stem digestibility and composition of plants of the derived populations. Leaf, sheath, and stem IVDMD, cell wall, cellulose, hemicellulose, and lignin concentration of switchgrass responded differently to breeding for tiller IVDMD indicating tissue specific regulation of plant composition. Breeding switchgrass for use in grazing systems should emphasize leaf and sheath composition. Stem composition can be modified to develop switchgrass cultivars for biomass energy.

Technical Abstract: Switchgrass (Panicum virgatum. L.) is a cross-pollinated, C4 species that is native to the prairies of temperate North America. Breeding to improve its forage quality has been conducted using post-heading, whole-tiller in vitro dry matter digestibility (IVDMD) as the selection criterion. One breeding cycle for low IVDMD and three cycles for high IVDMD were completed in a switchgrass population adapted to the USA mid-latitudes. Sward trials demonstrated that whole plant IVDMD had been improved. The objective of this study was to determine the effect of breeding for tiller IVDMD on leaf, sheath, and stem digestibility and composition of plants of the derived populations. Leaf, sheath, and stem IVDMD, cell wall, cellulose, hemicellulose, and lignin concentration of switchgrass responded differently to breeding for tiller IVDMD indicating tissue specific regulation of plant composition. Breeding switchgrass for use in grazing systems should emphasize leaf and sheath composition. Stem composition can be modified to develop switchgrass cultivars for biomass energy.