【作者】 孙男；

【导师】 李青； 袁小环；

【作者基本信息】 北京林业大学 ， 园林植物与观赏园艺， 2012， 硕士

【摘要】 观赏草是一类新型园林植物,具有良好的景观效果和生态功能。本文通过海水浇灌模拟盐胁迫试验,对O(CK)、25%、50%、75%和100%海水胁迫处理下莎草科(Cyperaceae)和禾本科(Poaceae)共20种观赏草幼苗的生长及生理情况进行了研究。根据25%海水胁迫下相关生长和生理指标的聚类分析结果及海水胁迫下植株的平均死亡率对20种观赏草的耐盐性进行了分级。研究结果如下：1、随着海水浓度升高,20种观赏草的株高、冠幅(分蘖数)、生物量、根冠比和叶绿素相对含量(叶绿素含量)均呈下降趋势,枯叶率则呈上升趋势,且耐盐性较强的观赏草变化幅度较小。2、随着海水浓度的升高,芨芨草与8种苔草的叶片相对电导率、丙二醛含量和超氧化物歧化酶活性均呈上升趋势；耐盐性较强的观赏草的叶片相对电导率和丙二醛含量变化幅度较小,而超氧化物歧化酶活性变化幅度较大。3、芨芨草、丽色画眉草和尖嘴苔草的净光合速率、气孔导度和蒸腾速率均随着海水浓度的升高而呈下降趋势,胞间C02浓度则呈上升趋势,且各项光合指标的变化幅度由大到小依次为：尖嘴苔草>丽色画眉草>芨芨草。4、根据试验结束时植株的平均死亡率可将20种观赏草的耐盐性分为5个等级：芨芨草的平均死亡率为零,耐盐性极强；狼尾草、知风草、丽色画眉草、‘斑叶’芒和‘细叶’芒的平均死亡率低于25%,耐盐性较强；尖嘴苔草、翼果苔草、披针叶苔草、青绿苔草、荻、‘玲珑’芒、‘花叶’芒和‘悍’芒的平均死亡率均未超过50%,耐盐性中等；棕榈叶苔草、矮丛苔草、拂子茅和‘晨光’芒的平均死亡率均介于50%和75%之间,耐盐性较弱；华北苔草和溪水苔草的平均死亡率均高于75%,耐盐性极弱。5、在本试验条件下,20种观赏草的耐盐性分级结果如下：芨芨草的耐盐性最强；尖嘴苔草、翼果苔草、披针叶苔草、知风草、丽色画眉草、狼尾草、‘细叶’芒和‘斑叶’芒的耐盐性较强；矮丛苔草、青绿苔草、荻、‘晨光’芒和‘玲珑’芒的耐盐性中等；棕榈叶苔草、华北苔草、拂子茅、‘花叶’芒和‘悍’芒的耐盐性较弱；溪水苔草的耐盐性最弱。本研究首次利用海水浇灌模拟盐胁迫条件进行植物的耐盐性评价,初步筛选出耐盐性最强的芨芨草和8种耐盐性较强的观赏草,为改善滨海盐渍土地区生态环境提供了参考。更多还原

【Abstract】 Ornamental grass with good visual effects and ecological functions is a new type of garden plants. Growth and physiological conditions of seedlings of20ornamental grasses in families Poaceae and Cyperaceae under0(control),25%,50%,75%and100%seawater stress were studied by utilizing seawater irrigation to simulate salt stress experiment. These20ornamental grasses’salt tolerance was classified according to plants’average death rate and cluster analysis results of related growth indicators and physiological indicators under25%seawater stress.The results are as follows:K With rising of seawater concentration,height,canopy width (tiller number),biomass,root/shoot ratio and chlorophyll relative content(chlorophyll content)of20ornamental grasses all show downward trends,while the percentage of withered leaves all show upward trends.And the higher salt tolerance plants have a smaller variation scopes.2、With rising of seawater concentration, relative electrical conductivity of leaves, MDA content and SOD activity of Achnatherum splendens (Trin.) Nevski and8Carex species all show upward trends; relative electrical conductivity of leaves and MDA content of the ornamental grass taxa with high salt tolerance have smaller variation scopes,while the SOD activity varies larger.3、With rising of seawater concentration.the net photosynthetic rate.stomatal conductance and transpiration rate of Achnatherum splendens (Trin.) Nevski, Eragrostis spectabilis (Pursh) Steud. and Carex leiorhyncha C. A. Mey. all show downward trends, while the intercellular CO2concentration all show upward trends, and the variation scopes of the photosynthetic indicators are sized down as follows: Carex leiorhyncha C. A. Mey.> Eragrostis spectabilis (Pursh) Steud.> Achnatherum splendens (Trin.) Nevski.4、According to the average death rate of plants in the end of the experiment, the salt tolerance of 20ornamental grasses can be divided into5grades:the average death rate of Achmatherum splendens (Trin.) Nevski. is zero with the highest salt tolerance; the average death rates of Penniseium alopecuroides (L.) Spreng.. Eragroslis ferruginea (Thunb.) Beauv, E. spectabilis (Pursh) Steud., Miscanthus sinensis "Zebrinus’ and M. sinensis’Gracillimus’are below25%with higher salt tolerance; the average death rates of C. leiorhyncha C. A. Mey., C. neurocarpa Maxim., C. lanceolata Boott, C. leucochlora Bge., Miscanthus sacchariflorus (Maxim.) Hack., M. sinensis’Yaku Jima’, M. sinensis "Variegatus" and M. sinensis "Malepartus" are between25%to50%with middle salt tolerance; the average death rates of C. muskingumensis "Oehme". C. humilis Leyss. var. nana, Calamagrostis brachytricha Steud. and M. sinensis’Morning light’are between50%to75%with lower salt tolerance: the average death rates of C. hancockianu Maxim, and C. for/icula Franch. are above75%with lowest salt tolerance.5、Under these experimental conditions.the classification of20ornamental grasses" salt tolerance is as follows:A. splendens is the highest:C. leiorhyncha. C. neurocarpa, C. lanceolata. E. ferruginea. E. spectabilis. P. alopecuroides. M. sinensis "Gracillimus" and M. sinensis’Zebrinus’are higher; C. humilis. C. leucochlora, M. sacchariflorus. M. sinensis "Morning light" and M sinensis’Yaku Jima’are middle; C. inuskingiunensis. C. hancockiana.C. brachylricha. M. sinensis "Variegatus" and M. sinensis ’Malepartus’are lower; C. forficula is the lowest.The research is the first attempt to utilize seawater irrigation to simulate salt stress condition to conduct the salt tolerance assessment of the plants. A. splendens and other8ornamental grasses with higher salt tolerance are chosen through preliminary screening, which provides a reference for improving the ecological environment in the coastal saline soil area.更多还原