title: Genome-wide association mapping and biochemical markers reveal that seed ageing and longevity are intricately affected by genetic background and developmental and environmental conditions in barley.
abstract: Globally, over 7.4 million accessions of crop seeds are stored in gene banks, and conservation of genotypic variation is pivotal for breeding. We combined genetic and biochemical approaches to obtain a broad overview of factors that influence seed storability and ageing in barley (Hordeum vulgare). Seeds from a germplasm collection of 175 genotypes from four continents grown in field plots with different nutrient supply were subjected to two artificial ageing regimes. Genome-wide association mapping revealed 107 marker trait associations, and hence, genotypic effects on seed ageing. Abiotic and biotic stresses were found to affect seed longevity. To address aspects of abiotic, including oxidative, stress, two major antioxidant groups were analysed. No correlation was found between seed deterioration and the lipid-soluble tocochromanols, nor with oil, starch and protein contents. Conversely, the water-soluble glutathione and related thiols were converted to disulphides, indicating a strong shift towards more oxidizing intracellular conditions, in seeds subjected to long-term dry storage at two temperatures or to two artificial ageing treatments. The data suggest that intracellular pH and (bio)chemical processes leading to seed deterioration were influenced by the type of ageing or storage. Moreover, seed response to ageing or storage treatment appears to be significantly influenced by both maternal environment and genetic background.
authors.affiliation: Genebank Department, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK Gatersleben), Stadt Seeland, Germany.
authors.forename: Manuela
authors.initials: M
authors.lastname: Nagel
authors.forename: Ilse
authors.initials: I
authors.lastname: Kranner
authors.forename: Kerstin
authors.initials: K
authors.lastname: Neumann
authors.forename: Hardy
authors.initials: H
authors.lastname: Rolletschek
authors.forename: Charlotte E
authors.initials: CE
authors.lastname: Seal
authors.forename: Louise
authors.initials: L
authors.lastname: Colville
authors.forename: Beatriz
authors.initials: B
authors.lastname: Fernández-Marín
authors.forename: Andreas
authors.initials: A
authors.lastname: Börner
mesh_terms: D002874:Chromosome Mapping; D059647:Gene-Environment Interaction; D014644:Genetic Variation; D055106:Genome-Wide Association Study; D005978:Glutathione / Q000032:analysis; D001467:Hordeum / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D008136:Longevity / Q000235:genetics; D012639:Seeds / Q000737:chemistry / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D024508:Tocotrienols / Q000032:analysis
chemical_list: D024508:Tocotrienols; D005978:Glutathione
keywords: accelerated seed ageing; gene bank; genotype; glutathione; seed deterioration; seed longevity; storage conditions; stress