Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/30/2005
Publication Date: N/A
Technical Abstract: 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.