title: Role of mucilage in the germination of Artemisia sphaerocephala (Asteraceae) achenes exposed to osmotic stress and salinity.
abstract: Artemisia sphaerocephala (Asteraceae) is one of the pioneer species in moving and semi-stable sand dunes in the deserts of northwest China. The outer surface of A. sphaerocephala achenes contains a pectinaceous mucilage layer that can imbibe a large amount of water when wetted. We hypothesized that the mucilage can aid achene germination in heterogeneous environments. Germination of both intact achenes and those from which the mucilage had been removed (demucilaged) declined with increasing osmotic potential and NaCl concentration. However, the germination percentage of intact achenes was significantly higher than that of demucilaged achenes. The early seedling growth of intact achenes did not differ significantly from that of demucilaged achenes in either osmotic potential or NaCl solutions. Achene mucilage presumably plays an ecologically important role in the life cycle of A. sphaerocephala by aiding germination in osmotically- and saline-stressful habitats of the cold desert environment.
authors.affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Xuejun
authors.initials: X
authors.lastname: Yang
authors.forename: Ming
authors.initials: M
authors.lastname: Dong
authors.forename: Zhenying
authors.initials: Z
authors.lastname: Huang
mesh_terms: D000222:Adaptation, Physiological; D019306:Artemisia / Q000254:growth & development* / Q000502:physiology; D002681:China; D003889:Desert Climate; D017753:Ecosystem; D018525:Germination; D006023:Glycoproteins / Q000502:physiology; D009995:Osmosis; D010940:Plant Proteins / Q000502:physiology*; D011134:Polysaccharides / Q000502:physiology; D055049:Salt Tolerance; D036226:Seedlings / Q000254:growth & development; D012639:Seeds / Q000254:growth & development* / Q000502:physiology; D012965:Sodium Chloride; D013312:Stress, Physiological; D014867:Water / Q000502:physiology
chemical_list: D006023:Glycoproteins; D010940:Plant Proteins; D011134:Polysaccharides; D014867:Water; D012965:Sodium Chloride