title: A local dormancy cline is related to the seed maturation environment, population genetic composition and climate.
abstract: OBJECTIVE
  Seed dormancy varies within species in response to climate, both in the long term (through ecotypes or clines) and in the short term (through the influence of the seed maturation environment). Disentangling both processes is crucial to understand plant adaptation to environmental changes. In this study, the local patterns of seed dormancy were investigated in a narrow endemic species, Centaurium somedanum, in order to determine the influence of the seed maturation environment, population genetic composition and climate.
  
  
  METHODS
  Laboratory germination experiments were performed to measure dormancy in (1) seeds collected from different wild populations along a local altitudinal gradient and (2) seeds of a subsequent generation produced in a common garden. The genetic composition of the original populations was characterized using intersimple sequence repeat (ISSR) PCR and principal co-ordinate analysis (PCoA), and its correlation with the dormancy patterns of both generations was analysed. The effect of the local climate on dormancy was also modelled.
  
  
  RESULTS
  An altitudinal dormancy cline was found in the wild populations, which was maintained by the plants grown in the common garden. However, seeds from the common garden responded better to stratification, and their release from dormancy was more intense. The patterns of dormancy variation were correlated with genetic composition, whereas lower temperature and summer precipitation at the population sites predicted higher dormancy in the seeds of both generations.
  
  
  CONCLUSIONS
  The dormancy cline in C. somedanum is related to a local climatic gradient and also corresponds to genetic differentiation among populations. This cline is further affected by the weather conditions during seed maturation, which influence the receptiveness to dormancy-breaking factors. These results show that dormancy is influenced by both long-and short-term climatic variation. Such processes at such a reduced spatial scale highlight the potential of plants to adapt to fast environmental changes.
authors.affiliation: Jardín Botánico Atlántico, Universidad de Oviedo, Avda. del Jardín Botánico 2230, 33394 Gijón/Xixón, Spain. eduardofp@indurot.uniovi.es
authors.forename: Eduardo
authors.initials: E
authors.lastname: Fernández-Pascual
authors.forename: Borja
authors.initials: B
authors.lastname: Jiménez-Alfaro
authors.forename: Juli
authors.initials: J
authors.lastname: Caujapé-Castells
authors.forename: Ruth
authors.initials: R
authors.lastname: Jaén-Molina
authors.forename: Tomás Emilio
authors.initials: TE
authors.lastname: Díaz
mesh_terms: D000222:Adaptation, Physiological; D029966:Centaurium / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D017931:DNA Primers / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D004777:Environment; D005828:Genetics, Population; D005843:Geography; D018525:Germination; D016014:Linear Models; D018895:Microsatellite Repeats / Q000235:genetics; D057445:Plant Dormancy; D016133:Polymerase Chain Reaction; D012639:Seeds / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D013696:Temperature
chemical_list: D017931:DNA Primers; D018744:DNA, Plant
keywords: Centaurium somedanum; Gentianaceae; ISSR; PCoA; clinal variation; common garden; ecophysiology; endemic; germination; plant–climate interactions; seed dormancy; seed ecology