title: Fluctuating selection by water level on gynoecium colour polymorphism in an aquatic plant.
abstract: OBJECTIVE
  It has been proposed that variation in pollinator preferences or a fluctuating environment can act to maintain flower colour polymorphism. These two hypotheses were tested in an aquatic monocot Butomus umbellatus (Butomaceae) with a pink or white gynoecium in the field population.
  
  
  METHODS
  Pollinator visitation was compared in experimental arrays of equivalent flowering cymes from both colour morphs. Seed set was compared between inter- and intramorph pollination under different water levels to test the effect of fluctuating environment on seed fertility.
  
  
  RESULTS
  Overall, the major pollinator groups did not discriminate between colour morphs. Compared with the white morph, seed production in the pink morph under intermorph, intramorph and open pollination treatments was significantly higher when the water level was low but not when it was high. Precipitation in July was correlated with yearly seed production in the pink morph but not in the white morph.
  
  
  CONCLUSIONS
  The results indicated that the two colour morphs differed in their tolerance to water level. Our study on this aquatic plant provides additional evidence to support the hypothesis that flower colour polymorphism can be preserved by environmental heterogeneity.
authors.affiliation: College of Life Sciences, Wuhan University, Wuhan 430072, China.
authors.forename: Xiao-Xin
authors.initials: XX
authors.lastname: Tang
authors.forename: Shuang-Quan
authors.initials: SQ
authors.lastname: Huang
mesh_terms: D035961:Alismatales / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D003116:Color; D035264:Flowers / Q000378:metabolism* / Q000502:physiology; D054817:Pollination / Q000502:physiology*; D012639:Seeds / Q000502:physiology; D014867:Water / Q000378:metabolism
chemical_list: D014867:Water
references.citation: Evolution. 1995 Oct;49(5):1017-1022
references.pmid: 28564870
references.citation: J Integr Plant Biol. 2008 Sep;50(9):1178-82
references.pmid: 18924283
references.citation: Evolution. 1996 Apr;50(2):957-963
references.pmid: 28568918
references.citation: Am J Bot. 1999 Nov;86(11):1576-96
references.pmid: 10562249
references.citation: Evolution. 2000 Apr;54(2):691-5
references.pmid: 10937244
references.citation: Evolution. 1981 Jul;35(4):763-774
references.pmid: 28563131
references.citation: Am J Bot. 2001 Mar;88(3):447-54
references.pmid: 11250822
references.citation: Mol Ecol. 2003 Feb;12(2):331-44
references.pmid: 12535085
references.citation: Proc Natl Acad Sci U S A. 2001 May 22;98(11):6253-5
references.pmid: 11353863
references.citation: Genetics. 1993 Aug;134(4):1237-47
references.pmid: 8375658
references.citation: Am J Bot. 2005 Jun;92(6):920-30
references.pmid: 21652475
references.citation: Evolution. 2001 Jul;55(7):1269-82
references.pmid: 11525452
references.citation: New Phytol. 2001 Jul;151(1):237-241
references.pmid: 33873384
references.citation: Nature. 2002 Nov 28;420(6914):407-10
references.pmid: 12459781
references.citation: J Evol Biol. 2007 Jan;20(1):122-32
references.pmid: 17210005
references.citation: Evolution. 2007 Nov;61(11):2528-43
references.pmid: 17894812
references.citation: Evolution. 1984 Jul;38(4):796-803
references.pmid: 28555829
references.citation: New Phytol. 2005 Nov;168(2):487-98
references.pmid: 16219087
references.citation: Evolution. 2008 May;62(5):1076-85
references.pmid: 18298642
references.citation: Evolution. 1981 Mar;35(2):376-390
references.pmid: 28563376
references.citation: Mol Ecol. 2003 May;12(5):1113-24
references.pmid: 12694276
references.citation: Evolution. 2001 Jul;55(7):1283-98
references.pmid: 11525453
references.citation: Am J Bot. 2001 Dec;88(12):2204-13
references.pmid: 21669653