毛状副冠对高山植物喉毛花的适应意义
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摘要
高山地区生境极端,却拥有许多形态特化的植物,非生物因素在塑造花部性状及其进化过程中发挥着重要作用。该研究选取龙胆科典型高山植物喉毛花(Comastoma pulmonarium)为对象,探究其毛状副冠在多雨、强辐射的极端高山环境中的适应意义及其对植物雌雄繁殖适合度的影响。结果表明:通过比较自然状态和人工去除副冠的花,毛状副冠有效减少了雨水对花粉的冲刷(t=2.61,P<0.05),提高了受精比率(t=2.05,P<0.05),但是对种子的质量,即种子重量和种子萌发率的影响不显著。另外,花粉浸泡在蒸馏水中后,其萌发率显著低于蔗糖溶液中(t=30.67,P<0.001),表明毛状副冠能够有效减小雨水浸泡对花粉活力的影响;同时,与自然状态相比,去除毛状副冠后的花,经太阳暴晒后,其花粉萌发率同样极显著地降低(t=9.89,P<0.001),表明毛状副冠有效地避免了太阳辐射对花粉质量产生的不利影响。该研究结果表明喉毛花的毛状副冠结构是应对高山恶劣环境的一种适应策略,对植株的雌性和雄性繁殖成功都具有重要意义,从而进一步证实了非生物因素在植物花部特征演化中的重要作用。
Despite of the harsh environmental conditions,alpine regions have very specialized and diverse plants.Abiotic factors play important roles in the formation and evolution of floral traits of these alpine plants. In this paper,the hairy corona of alpine plant Comastoma pulmonarium was studied to explore the evolutionary and adaptive significance of this distinctive floral structure in the extreme alpine environment and its effects on plant reproductive fitness. The results showed that in artificially corona removed flowers,pollen grains in anthers( t = 2.61,P< 0.05) and fertilization rate( t= 2.05,P<0.05) decreased greatly after rain-wash. However,there were no significant differences of the seed weight and seed germination rate between artificially corona removed flowers and control flowers. Additionally,pollen germination rate reduced significantly due to water immersion( t = 30.67,P<0.001) and direct exposure to sunlight( t = 9.89,P<0.001),indicating that hairy corona could maintain viability of pollen grains in front of rain immersion and intense solar radiation. This study indicates that the hairy corona of C. pulmonarium has adaptive significance for both male and female reproductive success in the harsh environment of alpine regions,and further confirms selection on the flower morphology of alpine plants by abiotic factors.
Despite of the harsh environmental conditions,alpine regions have very specialized and diverse plants.Abiotic factors play important roles in the formation and evolution of floral traits of these alpine plants. In this paper,the hairy corona of alpine plant Comastoma pulmonarium was studied to explore the evolutionary and adaptive significance of this distinctive floral structure in the extreme alpine environment and its effects on plant reproductive fitness. The results showed that in artificially corona removed flowers,pollen grains in anthers( t = 2.61,P< 0.05) and fertilization rate( t= 2.05,P<0.05) decreased greatly after rain-wash. However,there were no significant differences of the seed weight and seed germination rate between artificially corona removed flowers and control flowers. Additionally,pollen germination rate reduced significantly due to water immersion( t = 30.67,P<0.001) and direct exposure to sunlight( t = 9.89,P<0.001),indicating that hairy corona could maintain viability of pollen grains in front of rain immersion and intense solar radiation. This study indicates that the hairy corona of C. pulmonarium has adaptive significance for both male and female reproductive success in the harsh environment of alpine regions,and further confirms selection on the flower morphology of alpine plants by abiotic factors.
引文
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BYNUM MR,SMITH WK,2001.Floral movements in response to thunderstorms improve reproductive effort in the alpine species Gentiana algida(Gentianaceae)[J].Am J Bot,88(6):1088-1095.
CORBET SA,PLUMRIDGE JR,1985.Hydrodynamics and the germination of oil-seed rape pollen[J].J Agric Sci,104(2):445-451.
DARWIN C,1859.The origin of species by means of natural selection:or,the preservation of favored races in the struggle for life[M].London,UK:John Murray.
DEMCHIK SM,DAY TA,1996.Effect of enhanced UV-B radiation on pollen quantity,quality,and seed yield on Brassica rapa(Brassicaceae)[J].Am J Bot,83(5):573-579.
FENG HY,AN LZ,TAN LL,et al,2002.Cumulative effect of solar ultraviolet-B radiation on pollen germination and tube growth of 19 species in vitro[J].Chin J Appl Ecol,13(7):814-818.[冯虎元,安黎哲,谭玲玲,等,2002.UV-B辐射对植物花粉萌发率和花粉管生长的累积效应[J].应用生态学报,13(7):814-818.]
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HE YP,DUAN YW,LIU JQ,et al,2005.Floral closure in response to temperature and pollination in Gentiana straminea Maxim.(Gentianaceae),an alpine perennial in the QinghaiTibetan Plateau[J].Plant Syst Evol,256(1-4):17-33.
HESLOP-HARRISON Y,2000.Control gates and microecology:The pollen-stigma interaction in perspective[J].Ann Bot,85(Suppl.1):5-13.
HUANG SQ,TAKAHASHI Y,DAFNI A,2002.Why does the flower stalk of Pulsatilla cernua(Ranunculaceae)bend during anthesis?[J].Am J Bot,89(10):1599-1603.
JACQUEMART AL,1996.Selfing in Narthecium ossifragum(Melanthiaceae)[J].Plant Syst Evol,203(1-2):99-110.
LI YN,ZHAO XQ,CAO GM,et al,2004.Analyses on climates and vegetation productivity background at Haibei Alpine Meadow Ecosystem Research Station[J].Plateau Meteorol,23(4):558-567.[李英年,赵新全,曹广民,等,2004.海北高寒草甸生态系统定位站气候、植被生产力背景的分析[J].高原气象,23(4):558-567.]
PENG DL,ZHANG ZQ,NIU Y,et al,2012.Advances in the studies of reproductive strategies of alpine plants[J].Biodivers Sci,20(3):286-299.[彭德力,张志强,牛洋,等,2012.高山植物繁殖策略的研究进展[J].生物多样性,20(3):286-299.]
SPERANZA A,CALZONI GL,PACINI E,1997.Occurrence of mono-or disaccharides and polysaccharide reserves in mature pollen grains[J].Sex Plant Reprod,10(2):110-115.
STRAUSS S,WHITTALL JB,2006.Non-pollinator agents of selection on floral traits[M]//HARDER LD,BARRETTSCH.Ecology and Evolution of Flowers.Oxford:Oxford University Press:120-138.
SUN JF,GONG YB,RENNER SS,et al,2008.Multifunctional bracts in the dove tree Davidia involucrata(Nyssaceae:Cornales):Rain protection and pollinator attraction[J].Am Nat,171(1):119-124.
SUN RY,LI QF,NIU CJ,et al,2002.Basic ecology[M].Beijing:Higher Education Press.[孙儒泳,李庆芬,牛翠娟,等,2002.基础生态学[M].北京:高等教育出版社.]
TADEY M,AIZEN M,2001.Why do flowers of a hummingbirdpollinated mistletoe face down?[J].Funct Ecol,15(6):782-790.
TORABINEJAD J,CALDWELL MM,FLINT SD,et al,1998.Susceptibility of pollen to UV-B radiation:An assay of34 taxa[J].Am J Bot,85(3):360-369.
WANG Y,2009.Pollination mechanism and ecological adaptation in Anisodus luridus and A.carniolicoides[D].Kunming:Kunming Institute of Botany,Chinese Academy of Sciences:12-14.[王赟,2009.铃铛子(Anisodus luridus)和赛莨菪(A.carniolicoides)的传粉机制与生态适应[D].昆明:中国科学院昆明植物研究所:12-14.]
ZHANG C,IRWIN RE,WANG Y,et al,2011.Selective seed abortion induced by nectar robbing in the selfing Comastoma pulmonarium[J].New Phytol,192(1):249-255.
ZHANG C,YANG YP,DUAN YW,2014.Pollen sensitivity to ultraviolet-B(UV-B)suggests floral structure evolution in alpine plants[J].Sci Relp,4:4520.
ZHU QL,YU GR,CAI F,et al,2005.Spatiaization research on ultraviolet radiation in China[J].Resourc Sci,27(1):108-113.[祝青林,于贵瑞,蔡福,等,2005.中国紫外辐射的空间分布特征[J].资源科学,27(1):108-113.]
BROWN K,2002.Floral evolution:A compromise on floral traits[J].Science,298(5591):45-46.
BYNUM MR,SMITH WK,2001.Floral movements in response to thunderstorms improve reproductive effort in the alpine species Gentiana algida(Gentianaceae)[J].Am J Bot,88(6):1088-1095.
CORBET SA,PLUMRIDGE JR,1985.Hydrodynamics and the germination of oil-seed rape pollen[J].J Agric Sci,104(2):445-451.
DARWIN C,1859.The origin of species by means of natural selection:or,the preservation of favored races in the struggle for life[M].London,UK:John Murray.
DEMCHIK SM,DAY TA,1996.Effect of enhanced UV-B radiation on pollen quantity,quality,and seed yield on Brassica rapa(Brassicaceae)[J].Am J Bot,83(5):573-579.
FENG HY,AN LZ,TAN LL,et al,2002.Cumulative effect of solar ultraviolet-B radiation on pollen germination and tube growth of 19 species in vitro[J].Chin J Appl Ecol,13(7):814-818.[冯虎元,安黎哲,谭玲玲,等,2002.UV-B辐射对植物花粉萌发率和花粉管生长的累积效应[J].应用生态学报,13(7):814-818.]
FENSTER CB,ARMBRUSTER WS,WILSON P,et al,2004.Pollination syndromes and floral specialization[J].Ann Rev Ecol Evol Syst,35:375-403.
HE YP,DUAN YW,LIU JQ,et al,2005.Floral closure in response to temperature and pollination in Gentiana straminea Maxim.(Gentianaceae),an alpine perennial in the QinghaiTibetan Plateau[J].Plant Syst Evol,256(1-4):17-33.
HESLOP-HARRISON Y,2000.Control gates and microecology:The pollen-stigma interaction in perspective[J].Ann Bot,85(Suppl.1):5-13.
HUANG SQ,TAKAHASHI Y,DAFNI A,2002.Why does the flower stalk of Pulsatilla cernua(Ranunculaceae)bend during anthesis?[J].Am J Bot,89(10):1599-1603.
JACQUEMART AL,1996.Selfing in Narthecium ossifragum(Melanthiaceae)[J].Plant Syst Evol,203(1-2):99-110.
LI YN,ZHAO XQ,CAO GM,et al,2004.Analyses on climates and vegetation productivity background at Haibei Alpine Meadow Ecosystem Research Station[J].Plateau Meteorol,23(4):558-567.[李英年,赵新全,曹广民,等,2004.海北高寒草甸生态系统定位站气候、植被生产力背景的分析[J].高原气象,23(4):558-567.]
PENG DL,ZHANG ZQ,NIU Y,et al,2012.Advances in the studies of reproductive strategies of alpine plants[J].Biodivers Sci,20(3):286-299.[彭德力,张志强,牛洋,等,2012.高山植物繁殖策略的研究进展[J].生物多样性,20(3):286-299.]
SPERANZA A,CALZONI GL,PACINI E,1997.Occurrence of mono-or disaccharides and polysaccharide reserves in mature pollen grains[J].Sex Plant Reprod,10(2):110-115.
STRAUSS S,WHITTALL JB,2006.Non-pollinator agents of selection on floral traits[M]//HARDER LD,BARRETTSCH.Ecology and Evolution of Flowers.Oxford:Oxford University Press:120-138.
SUN JF,GONG YB,RENNER SS,et al,2008.Multifunctional bracts in the dove tree Davidia involucrata(Nyssaceae:Cornales):Rain protection and pollinator attraction[J].Am Nat,171(1):119-124.
SUN RY,LI QF,NIU CJ,et al,2002.Basic ecology[M].Beijing:Higher Education Press.[孙儒泳,李庆芬,牛翠娟,等,2002.基础生态学[M].北京:高等教育出版社.]
TADEY M,AIZEN M,2001.Why do flowers of a hummingbirdpollinated mistletoe face down?[J].Funct Ecol,15(6):782-790.
TORABINEJAD J,CALDWELL MM,FLINT SD,et al,1998.Susceptibility of pollen to UV-B radiation:An assay of34 taxa[J].Am J Bot,85(3):360-369.
WANG Y,2009.Pollination mechanism and ecological adaptation in Anisodus luridus and A.carniolicoides[D].Kunming:Kunming Institute of Botany,Chinese Academy of Sciences:12-14.[王赟,2009.铃铛子(Anisodus luridus)和赛莨菪(A.carniolicoides)的传粉机制与生态适应[D].昆明:中国科学院昆明植物研究所:12-14.]
ZHANG C,IRWIN RE,WANG Y,et al,2011.Selective seed abortion induced by nectar robbing in the selfing Comastoma pulmonarium[J].New Phytol,192(1):249-255.
ZHANG C,YANG YP,DUAN YW,2014.Pollen sensitivity to ultraviolet-B(UV-B)suggests floral structure evolution in alpine plants[J].Sci Relp,4:4520.
ZHU QL,YU GR,CAI F,et al,2005.Spatiaization research on ultraviolet radiation in China[J].Resourc Sci,27(1):108-113.[祝青林,于贵瑞,蔡福,等,2005.中国紫外辐射的空间分布特征[J].资源科学,27(1):108-113.]