Candidate genes underlying QTL for flowering time and their interactions in a wide spring barley (Hordeum vulgare L.) cross
Ana M. Casas,
Carlota R. Gazulla,
Arantxa Monteagudo,
Carlos P. Cantalapiedra,
Marian Moralejo,
M. Pilar Gracia,
Francisco J. Ciudad,
William T.B. Thomas,
José L. Molina-Cano,
Scott Boden,
Bruno Contreras-Moreira,
Ernesto Igartua
Affiliations
Ana M. Casas
Department of Genetics and Plant Production, Aula Dei Experimental Station (EEAD-CSIC), Avda Montañana 1005, E-50059 Zaragoza, Spain; Corresponding author.
Carlota R. Gazulla
Department of Genetics and Plant Production, Aula Dei Experimental Station (EEAD-CSIC), Avda Montañana 1005, E-50059 Zaragoza, Spain
Arantxa Monteagudo
Department of Genetics and Plant Production, Aula Dei Experimental Station (EEAD-CSIC), Avda Montañana 1005, E-50059 Zaragoza, Spain
Carlos P. Cantalapiedra
Department of Genetics and Plant Production, Aula Dei Experimental Station (EEAD-CSIC), Avda Montañana 1005, E-50059 Zaragoza, Spain
Marian Moralejo
University of Lleida - AGROTECNIO Center, Avda. Rovira Roure 191, 25198 Lleida, Spain
M. Pilar Gracia
Department of Genetics and Plant Production, Aula Dei Experimental Station (EEAD-CSIC), Avda Montañana 1005, E-50059 Zaragoza, Spain
Francisco J. Ciudad
Instituto de Tecnología Agraria, Junta de Castilla y León, ITACyL, P.O. Box 172, 47071 Valladolid, Spain
William T.B. Thomas
The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK
José L. Molina-Cano
Institut de Recerca i Tecnología Agroalimentàries (UdL-IRTA), Avda Rovira Roure 191, 25198 Lleida, Spain
Scott Boden
John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK
Bruno Contreras-Moreira
Department of Genetics and Plant Production, Aula Dei Experimental Station (EEAD-CSIC), Avda Montañana 1005, E-50059 Zaragoza, Spain; Fundación ARAID, calle María de Luna 11, 50018 Zaragoza, Spain
Ernesto Igartua
Department of Genetics and Plant Production, Aula Dei Experimental Station (EEAD-CSIC), Avda Montañana 1005, E-50059 Zaragoza, Spain
Response to vernalization and photoperiod are the main determinants controlling the time to flowering in temperate cereals. While the individual genes that determine a plant’s response to these environmental signals are well characterized, the combinatorial effect on flowering time of allelic variants for multiple genes remains unresolved. This study investigated the genetic control of flowering-time in a biparental population of spring barley, derived from a wide cross between a late-flowering European and an early-flowering North-American cultivar. While the major flowering time genes are not segregating in the Beka × Logan cross, large variation in flowering was observed. We identified five QTL, with both parents found to contribute early alleles. The catalog of QTL discovered aligns with several candidate genes affecting flowering time in barley. The combination of particular alleles at HvCEN, HvELF3 and HvFT1 in Logan are responsible for the earliness of this cultivar. Interestingly, earliness for flowering could be further enhanced, with Beka found to contribute three early alleles, including a QTL co-locating with a HvFD-like gene, suggesting that there are diverse aspects of the flowering-time pathway that have been manipulated in these two cultivars. Epistatic interactions between flowering-time QTL or candidate genes were observed in field data and confirmed under controlled conditions. The results of this study link photoperiod-dependent flowering-time genes with earliness per se genes into a single model, thus providing a unique framework that can be used by geneticists and breeders to optimize flowering time in barley.
