【作者】 张燕利；

【导师】 高捍东；

【作者基本信息】 南京林业大学 ， 森林培育， 2010， 硕士

【摘要】 本文选用四种景天属植物佛甲草、反曲景天、八宝景天、红叶景天作为研究对象,对其进行干旱胁迫下植物形态观察、生理生化指标的研究和耐热性的比较,为今后屋顶绿化植物的选择提供理论依据。结果表明:1、干旱胁迫影响植物的外部形态。胁迫初期植物生长缓慢;中期叶片逐渐失水、萎蔫,红叶景天和佛甲草叶片变化比较明显;后期红叶景天和反曲景天叶片严重萎蔫、干枯、脱落,八宝景天和佛甲草相对变化较弱。2、干旱胁迫下,土壤含水量变化趋势较剧烈,前、中期土壤含水量极速下降,后期缓慢下降,趋势趋于平缓。叶片含水量下降幅度较小,佛甲草叶片失水率最低,红叶景天失水率最高。3、干旱胁迫下,随胁迫时间的延长,四种植物的叶片相对电导率缓慢上升,红叶景天上升速度最快,其它三种植物变化相对缓慢。可溶性蛋白含量呈先增加后降低的趋势,八宝景天增幅最大,其次为佛甲草和反曲景天,红叶景天增幅最小。八宝景天、反曲景天MDA含量增加缓慢,红叶景天增加幅度较大。叶片游离脯氨酸含量逐渐增加,红叶景天增加缓慢,佛甲草增加趋势最为剧烈。四种植物SOD活性都呈现先上升后下降的趋势。可溶性糖含量先下降,胁迫10d后逐渐增加。4、运用电导率法对植物的耐热性进行测定,依据半致死温度,植物的耐热性强弱依次为:八宝景天>佛甲草>反曲景天>红叶景天。更多还原

【Abstract】 This paper had chosen four kinds of sedum plants as the research objects which were Sedum lineare、Sedum reflexum、Sedum spectabile and Sedum spurium "Coccineum". The research made two experiments, one observed the plants morphology and studied physiology and biochemistry features when the plants were under drought stress; the other was to compare the heat resistance. The main results were shown as follows:1. Drought stress had an effect on the morphology of plants. In the early days on drought stress, plants grew up slowly; during the middle stage, the leaves began to lose water and wilt, and the leaves of Sedum lineare and Sedum spurium "Coccineum" changed obviously; late under drought stress, the leaves of Sedum spurium "Coccineum" and Sedum reflexum wilted seriously, and began to dried-up and fall off, but Sedum lineare and Sedum spectabile had relative small changes.2. Soil water content changed obviously under drought stress. During the early and middle stages soil water content went down rapidly whereas it went down slowly and gradually during the later stages. The decline of water content in leaves was small, and the dehydrating rate of Sedum lineare in leaves was the lowest and that of the Sedum spurium "Coccineum" is the highest.3. With the increasing time of drought stress, the relative electric conductivity in leaves went up slowly with the Sedum spurium“Coccineum”rising the highest and the other three relatively slowly. The soluble protein content in leaves presented the trend that first increased then decreased, the increase of Sedum spectabile was the highest, the next were Sedum lineare and Sedum reflexum, the Sedum spurium "Coccineum" was the lowest. The MDA content in leaves of Sedum spectabile and Sedum reflexum increased slowly and that of Sedum spurium "Coccineum" increased rapidly. The content of free proline in leaves increased gradually, Sedum spurium "Coccineum" changed slowly and Sedum lineare increased more obviously. The SOD activity of four kinds of plants all presented the trend that first increased and then decreased. The soluble sugar content began to reduce at first ,but increased after 10 days under drought stress.4. Adopting the relative electric conductivity method, the paper studied the heat resistance of plants. According to the half lethal temperature, the order of the strengths and weakness of heat-resistance of four kinds of plants were: Sedum spectabile>Sedum lineare >Sedum reflexum>Sedum spurium "Coccineum".更多还原