title: Seed development and maturation in early spring-flowering Galanthus nivalis and Narcissus pseudonarcissus continues post-shedding with little evidence of maturation in planta.
abstract: OBJECTIVE
  Seeds of the moist temperate woodland species Galanthus nivalis and Narcissus pseudonarcissus, dispersed during spring or early summer, germinated poorly in laboratory tests. Seed development and maturation were studied to better understand the progression from developmental to germinable mode in order to improve seed collection and germination practices in these and similar species.
  
  
  METHODS
  Phenology, seed mass, moisture content and ability to germinate and tolerate desiccation were monitored during seed development until shedding. Embryo elongation within seeds was investigated during seed development and under several temperature regimes after shedding.
  
  
  RESULTS
  Seeds were shed at high moisture content (>59 %) with little evidence that dry mass accumulation or embryo elongation were complete. Ability to germinate developed prior to the ability of some seeds to tolerate enforced desiccation. Germination was sporadic and slow. Embryo elongation occurred post-shedding in moist environments, most rapidly at 20 °C in G. nivalis and 15 °C in N. pseudonarcissus. The greatest germination also occurred in these regimes, 78 and 48 %, respectively, after 700 d.
  
  
  CONCLUSIONS
  Seeds of G. nivalis and N. pseudonarcissus were comparatively immature at shedding and substantial embryo elongation occurred post-shedding. Seeds showed limited desiccation tolerance at dispersal.
authors.affiliation: Seed Conservation Department, Royal Botanic Gardens, Kew, Wakehurst Place, Ardingly, West Sussex RH17 6TN, UK. r.newton@kew.org
authors.forename: Rosemary J
authors.initials: RJ
authors.lastname: Newton
authors.forename: Fiona R
authors.initials: FR
authors.lastname: Hay
authors.forename: Richard H
authors.initials: RH
authors.lastname: Ellis
mesh_terms: D000222:Adaptation, Physiological; D018533:Biomass; D003890:Desiccation; D035264:Flowers / Q000254:growth & development / Q000502:physiology*; D005638:Fruit / Q000254:growth & development; D027801:Galanthus / Q000196:embryology*; D018525:Germination / Q000502:physiology*; D006813:Humidity; D031427:Narcissus / Q000196:embryology*; D012621:Seasons; D012639:Seeds / Q000254:growth & development*