Plant & Animal Genomes XIV Conference

January 14-18, 2006
Town & Country Convention Center
San Diego, CA

QTL Mapping Of Traits Differentiating Turf-Type Lolium perenne And Lolium multiflorum

Rebecca N. Brown¹ , Reed E. Barker² , Scott E. Warnke³ , Leah A. Brilman⁴ , Geunhwa Jung⁵ , Sung-Chur Sim⁵ , M. A. Rouf Mian⁶

¹  University of Rhode Island, Depratment of Plant Sciences, Kingston, RI 02881 USA

²  USDA-ARS National Forage Seed Production Research Center, 3450 SW Campus Way, Corvallis, OR 97331, USA

³  USDA-ARS 10300 Baltimore Avenue, Beltsville, MD 20705 USA

⁴  Seed Research of Oregon, Corvallis, OR 97333 USA

⁵  University of Wisconsin, Department of Plant Pathology, Madison, WI 53706, USA

⁶  USDA-ARS, 1680 Madison Avenue, Wooster, OH 44691

Ryegrasses (Lolium spp.) are cool-season grasses used for both turf and pasture. Knowledge of genes controlling morphological differences between annual and perennial types and between turf and forage types would help in understanding relationships among species, assist breeders in turfgrass improvement, and permit more accurate seed purity testing. Quantitative trait loci (QTLs) were identified for twenty traits related to flowering, plant size, plant appearance and seed yield in ryegrass using a turf-type perennial (Lolium perenne L.) x annual (or Italian) (Lolium multiflorum Lam.) hybrid mapping population. The objective of this ongoing research was to identify candidate gene regions associated with differences between turf-type perennial ryegrass and forage-type annual ryegrass. The population was studied in the field at three locations for two years. QTLs were detected for anthesis date, vernalization, plant height, the size of various plant structures, tiller number, growth habit, plant color, vigor, seed set and seed weight. A number of traits were significantly correlated with each other, and coincident QTLs were identified. Linkage group 4 has the most QTLs, including the QTLs for vernalization response and multiple QTLs for anthesis date. The clustering of QTLs for other traits on linkage group 4 may be a result of selection for flowering time. Most traits were also controlled by QTLs on other linkage groups. Environment significantly affects morphology, and QTLs differed across locations.