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United States Department of Agriculture

Agricultural Research Service

Title: Linkage Mapping of Qtls for Morphological Traits in Ryegrass: Seed Traits

Authors
item Brown, Rebecca - OREGON STATE UNIVERSITY
item Barker, Reed
item Warnke, Scott
item Mian, Rouf
item Jung, Geunhwa - UNIV OF WISCONSIN
item Sim, Sung-Chur - UNIV OF WISCONSIN

Submitted to: American Society of Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: August 31, 2004
Publication Date: N/A

Interpretive Summary: Ryegrasses (Lolium spp.) are cool-season grasses used for both turf and pasture. Knowledge of genes controlling morphological traits important in seed production would help in understanding relationships among species and assist breeders in plant improvement. Quantitative trait loci (QTLs) for a number of traits associated with seed yield of ryegrass were identified using a perennial (L. perenne L.) x annual (L. multiflorum Lam.) hybrid mapping population. The objective of this research was to identify the genes responsible for the morphological differences between perennial ryegrass and annual ryegrass. The population was studied in the field in three locations for two years. QTLs were identified for days to anthesis, floret number, spikelet number, seed number, spikelet weight, seed weight, spike weight, spike length, and lemma and palea dimensions. Anthesis data was significantly correlated across locations within years, but not across years. Anthesis date was negatively correlated with seed traits. QTLs for anthesis date and seed traits clustered on the map, indicating that the association of earlier flowering from L. multiflorum with high seed yield is at least partially due to linked genes or pleitropy. The majority of the linkage groups contain QTLs for anthesis date and seed traits, reflecting the genetic complexity of these characters in ryegrass.

Technical Abstract: Ryegrasses (Lolium spp.) are cool-season grasses used for both turf and pasture. Knowledge of genes controlling morphological traits important in seed production would help in understanding relationships among species and assist breeders in plant improvement. Quantitative trait loci (QTLs) for a number of traits associated with seed yield of ryegrass were identified using a perennial (L. perenne L.) x annual (L. multiflorum Lam.) hybrid mapping population. The objective of this research was to identify the genes responsible for the morphological differences between perennial ryegrass and annual ryegrass. The population was studied in the field in three locations for two years. QTLs were identified for days to anthesis, floret number, spikelet number, seed number, spikelet weight, seed weight, spike weight, spike length, and lemma and palea dimensions. Anthesis data was significantly correlated across locations within years, but not across years. Anthesis date was negatively correlated with seed traits. QTLs for anthesis date and seed traits clustered on the map, indicating that the association of earlier flowering from <I>L. multiflorum</I> with high seed yield is at least partially due to linked genes or pleitropy. The majority of the linkage groups contain QTLs for anthesis date and seed traits, reflecting the genetic complexity of these characters in ryegrass.

Last Modified: 8/1/2014
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