title: Intermediate complex morphophysiological dormancy in seeds of the cold desert sand dune geophyte Eremurus anisopterus (Xanthorrhoeaceae; Liliaceae s.l.).
abstract: OBJECTIVE
  Little is known about morphological (MD) or morphophysiological (MPD) dormancy in cold desert species and in particular those in Liliaceae sensu lato, an important floristic element in the cold deserts of Central Asia with underdeveloped embyos. The primary aim of this study was to determine if seeds of the cold desert liliaceous perennial ephemeral Eremurus anisopterus has MD or MPD, and, if it is MPD, then at what level.
  
  
  METHODS
  Embryo growth and germination was monitored in seeds subjected to natural and simulated natural temperature regimes and the effects of after-ripening and GA3 on dormancy break were tested. In addition, the temperature requirements for embryo growth and dormancy break were investigated.
  
  
  RESULTS
  At the time of seed dispersal in summer, the embryo length:seed length (E:S) ratio was 0·73, but it increased to 0·87 before germination. Fresh seeds did not germinate during 1 month of incubation in either light or darkness over a range of temperatures. Thus, seeds have MPD, and, after >12 weeks incubation at 5/2 °C, both embryo growth and germination occurred, showing that they have a complex level of MPD. Since both after-ripening and GA3 increase the germination percentage, seeds have intermediate complex MPD.
  
  
  CONCLUSIONS
  Embryos in after-ripened seeds of E. anisopterus can grow at low temperatures in late autumn, but if the soil is dry in autumn then growth is delayed until snowmelt wets the soil in early spring. The ecological advantage of embryo growth phenology is that seeds can germinate at a time (spring) when sand moisture conditions in the desert are suitable for seedling establishment.
authors.affiliation: Xinjiang Key Laboratory of Grassland Resources and Ecology and Ministry of Education Key Laboratory for Western Arid Region Grassland Resources and Ecology, College of Grassland and Environment Sciences, Xinjiang Agricultural University, Ürümqi 830052, China.
authors.forename: Jannathan
authors.initials: J
authors.lastname: Mamut
authors.affiliation: Xinjiang Key Laboratory of Grassland Resources and Ecology and Ministry of Education Key Laboratory for Western Arid Region Grassland Resources and Ecology, College of Grassland and Environment Sciences, Xinjiang Agricultural University, Ürümqi 830052, China tandunyan@163.com ccbask0@uky.edu.
authors.forename: Dun Yan
authors.initials: DY
authors.lastname: Tan
authors.affiliation: Xinjiang Key Laboratory of Grassland Resources and Ecology and Ministry of Education Key Laboratory for Western Arid Region Grassland Resources and Ecology, College of Grassland and Environment Sciences, Xinjiang Agricultural University, Ürümqi 830052, China Department of Biology Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546, USA tandunyan@163.com ccbask0@uky.edu.
authors.forename: Carol C
authors.initials: CC
authors.lastname: Baskin
authors.affiliation: Xinjiang Key Laboratory of Grassland Resources and Ecology and Ministry of Education Key Laboratory for Western Arid Region Grassland Resources and Ecology, College of Grassland and Environment Sciences, Xinjiang Agricultural University, Ürümqi 830052, China Department of Biology.
authors.forename: Jerry M
authors.initials: JM
authors.lastname: Baskin
mesh_terms: D003080:Cold Temperature; D003624:Darkness; D003889:Desert Climate; D004463:Ecology; D018525:Germination / Q000502:physiology; D008027:Light; D019668:Liliaceae / Q000033:anatomy & histology / Q000254:growth & development* / Q000502:physiology / Q000528:radiation effects; D057445:Plant Dormancy / Q000502:physiology*; D012621:Seasons; D012639:Seeds / Q000033:anatomy & histology / Q000254:growth & development* / Q000502:physiology / Q000528:radiation effects; D012987:Soil
chemical_list: D012987:Soil
keywords: Cold desert perennial ephemeral; Eremurus anisopterus; embryo growth; germination ecology; germination phenology; seed morphophysiological dormancy