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Submitted to: Crop Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 9/3/2013 Publication Date: 1/1/2014 Citation: Larson, S.R., Jensen, K.B., Robins, J.G., Waldron, B.L. 2014. Genes and quantitative trait loci controlling biomass yield and forage quality traits in perennial wildrye. Crop Science. 54:111-126. Interpretive Summary: Native perennial grasses provide vital ecosystem services and have potential use as low-input feedstocks in diverse environments. Cool-season grasses, in particular, dominate temperate growing regions throughout higher elevations and latitudes of the World. However, innovative breeding methods are needed to domesticate and improve wild species for new agricultural uses. Basin wildrye is the largest native grass in western North America, but its high growing point is susceptible to defoliation. Creeping wildrye is a shorter less productive grass with durable rhizomes and higher forage quality. In this study, it was shown that creeping x basin wildrye hybrids have greater biomass production compared to the parental species. Moreover, experimental populations derived from these creeping x basin wildrye hybrids were used to identify chromosome regions controlling plant height, rhizome spreading, flowering, post-flowering biomass yield, cellulosic fiber, lignin, and protein traits using a genetic map comprised of 376 expressed gene sequence tags including 26 lignin biosynthesis gene loci and 424 other DNA markers. Genetic markers associated with these biomass traits will be used to develop superior wildrye hybrids with improved biomass yield and forage quality for winter grazing and other possible uses in the Great Basin and other cold-growing regions of western North America. Technical Abstract: Native perennial grasses provide vital ecosystem services and have potential use as low-input feedstocks in diverse environments. Cool-season grasses, in particular, dominate temperate growing regions throughout higher elevations and latitudes of the World. However, innovative breeding methods are needed to domesticate and improve wild species for new agricultural uses. Basin wildrye (Leymus cinereus) is the largest native grass in western North America, but its high growing point is susceptible to defoliation. Creeping wildrye (Leymus triticoides) is a shorter less productive grass with durable rhizomes and higher forage quality. In this study, it was shown that creeping x basin wildrye hybrids have greater biomass production compared to the parental species. Moreover, experimental populations derived from creeping x basin wildrye hybrids were used to identify quantitative trail loci (QTLs) controlling plant height, rhizome spreading, flowering, post-anthesis biomass yield, cellulosic fiber, lignin, and protein traits using a linkage map comprised of 376 Leymus expressed gene sequence tags (ESTs) including 26 lignin biosynthesis gene loci and 424 other DNA markers. The genome positions of QTLs controlling biomass yield and composition in Leymus were aligned to important agronomic genes controlling dwarfing, photoperiod response, and vernalization in wheat and barley using the Brachypodium genome reference sequence. Evidence suggests that genetic mechanisms controlling flowering, plant height, and stem branching traits are conserved among temperate grasses and reveal pathways for improving biomass production. Thus, genetic markers identified in this study will be used to develop wildrye hybrids with improved biomass yield and forage quality for winter grazing and other possible uses in the Great Basin and other cold-growing regions of western North America. |
