三种锦鸡儿属植物水力结构特征及其干旱适应策略
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摘要
水分胁迫是干旱半干旱区限制植物生长的主要因素。以干旱半干旱区的3种锦鸡儿属植物为研究对象,从生态适应策略角度来分析3种锦鸡儿植物产生生态分离的原因。对三种锦鸡儿属植物茎干叶片的显微结构、生理功能(导水率、光合速率以及水分利用效率)进行测定,并统计了3种锦鸡儿植株的形态特征,如一、二级枝的直径、长度、末端叶面积。结果表明:三种锦鸡儿属植物都能形成较小的导管直径来适应旱生环境,但是在导水结构上又表现出一定的差异性。中间锦鸡儿的导管直径最小,次脉密度和最大净光合速率最大;柠条锦鸡儿的导管直径、叶片厚度和比叶重(LMA)最大。小叶锦鸡儿在导水率下降50%时的水势(P_(50))最大,水分胁迫时极易发生栓塞,但正是由于导管的栓塞降低了水分运输效率,使其在旱生环境中能够通过减少水分的供应来降低水分的丧失,从而保证自身生长的水分需求;而中间锦鸡儿则主要通过减小导管直径来适应旱生环境;柠条锦鸡儿的水分利用效率最高,抗栓塞能力最强,抗旱性最好,同时柠条锦鸡儿可以通过减少蒸腾面积来减少水分的丧失。植物的导管直径大小、叶片厚度、LMA、叶脉密度对植物导水速率、光合速率等生理功能都有一定的影响。
Water stress is a main growth-limiting factor for plants in arid and semi-arid regions. In this study,we evaluated the hydraulic architecture traits and physiological functions of three Caragana genus species(Caragana microphylla,Caragana intermedia,Caragana korshinskii) in different drought environments. The aim was to explore causes of ecological separation from ecological adaption strategies of three Caragana species. Field methods were used to survey morphological traits such as the first and secondary branch diameters and lengths. Measured hydraulic architecture traits included xylem conduit,leaf vein density,leaf thickness,and leaf mass area. The physiological functions included hydraulic conductance,photosynthesis,and water use efficiency. Our results showed that all three Caragana species had small conduit diameter structures to adapt to xeric environments,but also showed some differences in other hydraulic architecture traits. Conduit diameters of C. intermedia were smaller than those of the other species,whereas leaf minor vein density and maximum photosynthesis rates were the highest. Leaf thickness,leaf mass area,and conduits diameter of C. korshinskii were larger than those of the other species. Caragana microphylla showed the largest P_(50),suggesting that embolism was easier underwater stress and xylem embolism reduced water transportation efficiency to maintain the requirements for growth by reducing the water supply in an arid environment. Caragana intermedia had reduced xylem conduit diameters to adapt to drought conditions. Caragana korshinskii exhibited the strongest ability to resist embolism and drought tolerance and reduced the water supply by decreasing the transpiration area. Xylem conduit size,leaf thickness,leaf mass area,and leaf vein density have important effects on plant physiology,such as hydraulic conductance and photosynthetic rate.
Water stress is a main growth-limiting factor for plants in arid and semi-arid regions. In this study,we evaluated the hydraulic architecture traits and physiological functions of three Caragana genus species(Caragana microphylla,Caragana intermedia,Caragana korshinskii) in different drought environments. The aim was to explore causes of ecological separation from ecological adaption strategies of three Caragana species. Field methods were used to survey morphological traits such as the first and secondary branch diameters and lengths. Measured hydraulic architecture traits included xylem conduit,leaf vein density,leaf thickness,and leaf mass area. The physiological functions included hydraulic conductance,photosynthesis,and water use efficiency. Our results showed that all three Caragana species had small conduit diameter structures to adapt to xeric environments,but also showed some differences in other hydraulic architecture traits. Conduit diameters of C. intermedia were smaller than those of the other species,whereas leaf minor vein density and maximum photosynthesis rates were the highest. Leaf thickness,leaf mass area,and conduits diameter of C. korshinskii were larger than those of the other species. Caragana microphylla showed the largest P_(50),suggesting that embolism was easier underwater stress and xylem embolism reduced water transportation efficiency to maintain the requirements for growth by reducing the water supply in an arid environment. Caragana intermedia had reduced xylem conduit diameters to adapt to drought conditions. Caragana korshinskii exhibited the strongest ability to resist embolism and drought tolerance and reduced the water supply by decreasing the transpiration area. Xylem conduit size,leaf thickness,leaf mass area,and leaf vein density have important effects on plant physiology,such as hydraulic conductance and photosynthetic rate.
引文
[1]Li J,Gao Y B,Zheng Z R,Gao Z L.Water relations,hydraulic conductance,and vessel features of Three Caragana species of the Inner Mongolia Plateau of China.Botanical Studies,2008,49(2):127-137.
[2]龚容,高琼.叶片结构的水力学特性对植物生理功能影响的研究进展.植物生态学报,2015,39(3):300-308.
[3]杨启良,张富仓,刘小刚,张楠,戈振扬.环境因素对植物导水率影响的研究综述.中国生态农业学报,2011,19(2):456-461.
[4]Lens F,Sperry J S,Christman M A,Choat B,Rabaey D,Jansen S.Testing hypotheses that link wood anatomy to cavitation resistance and hydraulic conductivity in the genus Acer.New Phytologist,2011,190(3):709-723.
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[7]Choat B.Predicting thresholds of drought-induced mortality in woody plant species.Tree Physiology,2013,33(7):669-671.
[8]Pittermann J,Sperry J.Tracheid diameter is the key trait determining the extent of freezing-induced embolism in conifers.Tree Physiology,2003,23(13):907-914.
[9]Stuart S A,Choat B,Martin K C,Holbrook N M,Ball M C.The role of freezing in setting the latitudinal limits of mangrove forests.New Phytologist,2007,173(3):576-583.
[10]Nardini A,Luglio J.Leaf hydraulic capacity and drought vulnerability:possible trade-offs and correlations with climate across three major biomes.Functional Ecology,2014,28(4):810-818.
[11]Sack L,Scoffoni C.Leaf venation:structure,function,development,evolution,ecology and applications in the past,present and future.New Phytologist,2013,198(4):983-1000.
[12]Hacke U G,Sperry J S,Pittermann J.Drought experience and cavitation resistance in six shrubs from the Great Basin,Utah.Basic and Applied Ecology,2000,1(1):31-41.
[13]Jacobsen A L,Agenbag L,Esler K J,Pratt R B,Ewers F W,Davis S D.Xylem density,biomechanics and anatomical traits correlate with water stress in 17 evergreen shrub species of the mediterranean-type climate region of South Africa.Journal of Ecology,2007,95(1):171-183.
[14]Thornthwaite C W.An approach toward a rational classification of climate.Geographical Review,1948,38(1):55-94.
[15]孟猛,倪健,张治国.地理生态学的干燥度指数及其应用评述.植物生态学报,2004,28(6):853-861.
[16]Johnson D M,Meinzer F C,Woodruff D R,Mc Culloh K A.Leaf xylem embolism,detected acoustically and by cryo-SEM,corresponds to decreases in leaf hydraulic conductance in four evergreen species.Plant,Cell&Environment,2009,32(7):828-836.
[17]Nardini A,Salleo S.Water stress-induced modifications of leaf hydraulic architecture in sunflower:co-ordination with gas exchange.Journal of Experimental Botany,2005,56(422):3093-3101.
[18]木巴热克·阿尤普,陈亚宁,郝兴明,李卫红,苏芮.极端干旱环境下的胡杨木质部水力特征.生态学报,2012,32(9):2748-2758.
[19]Nardini A,PedáG,Salleo S.Alternative methods for scaling leaf hydraulic conductance offer new insights into the structure-function relationships of sun and shade leaves.Functional Plant Biology,2012,39(5):394-401.
[20]Witkowski E T F,Lamont B B.Leaf specific mass confounds leaf density and thickness.Oecologia,1991,88(4):486-493.
[21]金鹰,王传宽.九种不同材性的温带树种叶水力性状及其权衡关系.植物生态学报,2016,40(7):702-710.
[22]Sperry J S.Hydraulic constraints on plant gas exchange.Agricultural and Forest Meteorology,2000,104(1):13-23.
[23]Cai J,Tyree M T.The impact of vessel size on vulnerability curves:data and models for within-species variability in saplings of aspen,Populus tremuloides Michx.Plant,Cell&Environment,2010,33(7):1059-1069.
[24]de Dios Miranda J,Padilla F M,Martínez-Vilalta J,Pugnaire F I.Woody species of a semi-arid community are only moderately resistant to cavitation.Functional Plant Biology,2010,37(9):828-839.
[25]周洪华,李卫红,木巴热克·阿尤普,徐茜.荒漠河岸林植物木质部导水与栓塞特征及其对干旱胁迫的响应.植物生态学报,2012,36(1):19-29.
[2]龚容,高琼.叶片结构的水力学特性对植物生理功能影响的研究进展.植物生态学报,2015,39(3):300-308.
[3]杨启良,张富仓,刘小刚,张楠,戈振扬.环境因素对植物导水率影响的研究综述.中国生态农业学报,2011,19(2):456-461.
[4]Lens F,Sperry J S,Christman M A,Choat B,Rabaey D,Jansen S.Testing hypotheses that link wood anatomy to cavitation resistance and hydraulic conductivity in the genus Acer.New Phytologist,2011,190(3):709-723.
[5]Lens F,Tixier A,Cochard H,Sperry J S,Jansen S,Herbette S.Embolism resistance as a key mechanism to understand adaptive plant strategies.Current Opinion in Plant Biology,2013,16(3):287-292.
[6]Martinez-Vilalta J,Mencuccini M,lvarez X,Camacho J,Loepfe L,Pi1ol J.Spatial distribution and packing of xylem conduits.American Journal of Botany,2012,99(7):1189-1196.
[7]Choat B.Predicting thresholds of drought-induced mortality in woody plant species.Tree Physiology,2013,33(7):669-671.
[8]Pittermann J,Sperry J.Tracheid diameter is the key trait determining the extent of freezing-induced embolism in conifers.Tree Physiology,2003,23(13):907-914.
[9]Stuart S A,Choat B,Martin K C,Holbrook N M,Ball M C.The role of freezing in setting the latitudinal limits of mangrove forests.New Phytologist,2007,173(3):576-583.
[10]Nardini A,Luglio J.Leaf hydraulic capacity and drought vulnerability:possible trade-offs and correlations with climate across three major biomes.Functional Ecology,2014,28(4):810-818.
[11]Sack L,Scoffoni C.Leaf venation:structure,function,development,evolution,ecology and applications in the past,present and future.New Phytologist,2013,198(4):983-1000.
[12]Hacke U G,Sperry J S,Pittermann J.Drought experience and cavitation resistance in six shrubs from the Great Basin,Utah.Basic and Applied Ecology,2000,1(1):31-41.
[13]Jacobsen A L,Agenbag L,Esler K J,Pratt R B,Ewers F W,Davis S D.Xylem density,biomechanics and anatomical traits correlate with water stress in 17 evergreen shrub species of the mediterranean-type climate region of South Africa.Journal of Ecology,2007,95(1):171-183.
[14]Thornthwaite C W.An approach toward a rational classification of climate.Geographical Review,1948,38(1):55-94.
[15]孟猛,倪健,张治国.地理生态学的干燥度指数及其应用评述.植物生态学报,2004,28(6):853-861.
[16]Johnson D M,Meinzer F C,Woodruff D R,Mc Culloh K A.Leaf xylem embolism,detected acoustically and by cryo-SEM,corresponds to decreases in leaf hydraulic conductance in four evergreen species.Plant,Cell&Environment,2009,32(7):828-836.
[17]Nardini A,Salleo S.Water stress-induced modifications of leaf hydraulic architecture in sunflower:co-ordination with gas exchange.Journal of Experimental Botany,2005,56(422):3093-3101.
[18]木巴热克·阿尤普,陈亚宁,郝兴明,李卫红,苏芮.极端干旱环境下的胡杨木质部水力特征.生态学报,2012,32(9):2748-2758.
[19]Nardini A,PedáG,Salleo S.Alternative methods for scaling leaf hydraulic conductance offer new insights into the structure-function relationships of sun and shade leaves.Functional Plant Biology,2012,39(5):394-401.
[20]Witkowski E T F,Lamont B B.Leaf specific mass confounds leaf density and thickness.Oecologia,1991,88(4):486-493.
[21]金鹰,王传宽.九种不同材性的温带树种叶水力性状及其权衡关系.植物生态学报,2016,40(7):702-710.
[22]Sperry J S.Hydraulic constraints on plant gas exchange.Agricultural and Forest Meteorology,2000,104(1):13-23.
[23]Cai J,Tyree M T.The impact of vessel size on vulnerability curves:data and models for within-species variability in saplings of aspen,Populus tremuloides Michx.Plant,Cell&Environment,2010,33(7):1059-1069.
[24]de Dios Miranda J,Padilla F M,Martínez-Vilalta J,Pugnaire F I.Woody species of a semi-arid community are only moderately resistant to cavitation.Functional Plant Biology,2010,37(9):828-839.
[25]周洪华,李卫红,木巴热克·阿尤普,徐茜.荒漠河岸林植物木质部导水与栓塞特征及其对干旱胁迫的响应.植物生态学报,2012,36(1):19-29.