干旱胁迫条件下6种喀斯特主要造林树种苗木叶片水势及吸水潜能变化  

Changes of leaf water potential and water absorption potential capacities of six kinds of seedlings in Karst mount area under different drought stress intensities:Taking six forestation seedlings in karst Mountainous region for example

作　　者：王丁[1,2] 姚健[2] 杨雪[1] 薛建辉[2] 

机构地区：[1]河南教育学院人口与生命科学系,河南郑州450046 [2]南京林业大学江苏省林业生态工程重点实验室,江苏南京210037

出　　处：《生态学报》2011年第8期2216-2226,共11页Acta Ecologica Sinica

基　　金：国家"十一五"科技支撑计划课题(2006BAD03A0303)

摘　　要：水势是反映植物水分亏缺或水分状况的一个直接指标,可用来确定植物受干旱胁迫的程度和抗旱能力高低。研究了6种喀斯特造林树种苗木在干旱胁迫条件下叶片水势及其吸水潜能的变化。结果表明:(1)随着胁迫强度的增加,6种树种不同生长时期,其叶片水势均表现出下降趋势,且不同干旱胁迫强度之间差异显著(P<0.002)。在干旱胁迫下,所有树种叶片水势均以生长旺期的下降幅度最大,生长末期次之,生长初期最小。在生长旺期,6个树种叶片水势最低值分别比对照下降了2.21MPa、2.14 MPa、3.57 MPa、2.89MPa、4.02MPa和3.07MPa。(2)侧柏苗木在生长初期轻度干旱条件下,其叶片水势胁迫指数只有0.150;在中度干旱胁迫条件下,其胁迫指数增加到0.559;在重度干旱胁迫条件下,达0.716,叶片水势下降超过70%。香樟苗木在生长初期轻度干旱胁迫条件下,其叶片水势胁迫指数就已达0.603,叶片水势下降超过了60%;在中度和重度干旱胁迫条件下,其水势胁迫指数相差不大。其它树种苗木的胁迫指数亦有与侧柏或香樟相似的变化趋势。(3)6个树种苗木在干旱胁迫条件下平均叶片水势与土壤水势差值大小排序为,生长初期:刺槐(1.261MPa)>香樟(0.850 MPa)>滇柏(0.846 MPa)>侧柏(0.568 MPa)>构树(0.524 MPa)>杜英(0.219 MPa);生长旺期:香樟(2.994 MPa)>刺槐(2.68 MPa)>侧柏(2.028 MPa)>滇柏(2.008 MPa)>杜英(1.824 MPa)>构树(1.543 MPa);生长末期:刺槐(0.692 MPa)>构树(0.687 MPa)>滇柏(0.653MPa)>侧柏(0.354 MPa)>香樟(0.338 MPa)>杜英(0.262 MPa)。(4)干旱胁迫复水24h后,不同生长阶段苗木叶片水势恢复指数随干旱胁迫强度的增加而逐渐减小。叶片水势恢复度按生长时期排序为:生长末期>生长旺期>生长初期。(5)利用隶属函数累加法将6个树种苗木的吸水潜能大小可排序为:侧柏>滇柏>刺槐>香樟>构树>杜英。Water potential is a direct index to represent water status or water deficit of plants and could be used to indicate their drought stress degree and drought-tolerance capacity.In this paper,Changes of leaf water potential and water absorption potential capacities of six tree species seedlings planted in Karst areas have been investigated.The main results were described as follows：（1） With the increase of water stress intensity,leaf water potential value of all six tree species seedlings among different growing stages represented decreasing trend.Meanwhile,there existed significant differences among those under different drought stress treatment（P0.002）.Under drought stress,the leaf water potential value of all seedlings came up to the largest decrease valence during fast growth stage,then the second during last growth stage and the lowest during early growth stage.During fast growth stage,the leaf water potential value of all six species seedlings increased by 2.21 MPa、2.14 MPa、3.57 MPa、2.89MPa、4.02MPa and 3.07MPa compared with the control.（2） At early growth stage,leaf water potential stress index of Platycladus orientalis（Linn.）Franco was only 0.150 under light drought stress,but 0.559 under moderate drought stress.Under severe drought stress,the leaf water potential stress index reached 0.716.And leaf water potential stress index of Cinnamomum camphora（Linn.）Presl already reached 0.603 at early growth stage under light drought stress.there was small difference between those under moderate drought stress and severe drought stress.The leaf water potential stress indexes of other tree species had a similar tendency.（3） Under drought stress,the average differences between leaf water potential and silo water potential could be ordered as follows： early growth stage ：Robinia pseudoacacia L.（1.261MPa） Cinnamomum camphora（Linn.）Presl（0.850 MPa） Fokienia hodginsii（Dunn） Henry et Thomas（0.846 MPa） Platycladus orientalis（Linn.）Franco（0.568 MPa） Broussoneti

关 键 词：干旱胁迫 苗木 生长阶段 叶片水势 吸水潜能 

分 类 号：S718.4[农业科学—林学]