3种灌木对干旱胁迫的生理响应

Physiological Response to Drought Stress of Three Shrubs

为确定灌木对干旱胁迫的生理响应,以天目琼花(Viburnum sargentii Koehne)、麻叶绣线菊(Spiraea cantoniensis Lour)和小紫珠(Callicarpa dichotoma Lour)幼苗为试验材料,采用盆栽控水法,设置4个水分梯度,分别为田间最大持水量的95%(对照)、75%(轻度干旱)、55%(中度干旱)和35%(重度干旱),研究干旱胁迫对3种灌木生理特性的影响。结果表明:随着干旱胁迫的加剧,3种灌木的w(总叶绿素)、w(叶绿素a)/w(叶绿素b)和w(类胡萝卜素)逐渐下降,并且w(叶绿素a)的降幅远大于w(叶绿素b)的。随着胁迫程度的增加,3种灌木叶片相对电导率逐渐增大,叶片相对含水量逐渐下降。通过隶属函数综合分析可知,3种灌木中天目琼花抗旱性最强,麻叶绣线菊次之,小紫珠抗旱性最差。

The seedlings of Viburnum sargentii Koehne,Spiraea cantoniensis Lour and Callicarpa dichotoma Lour were used as materials to determine their physiological response to drought stress.Four moisture gradients were set,including 95% of maximum field water holding capacity(as the control),75%(mild drought),55%(moderate drought) and 35%(severe drought),respectively.The results showed that the chlorophyll,chlorophyll a/b and carotenoid contents of three shrubs decreased gradually with the aggravation of drought stress,and the decrease degree of chlorophyll a was much greater than that of chlorophyll b.With drought stress enlarged,the relative electrical conductivity of the leaves increased gradually while the relative water content decreased gradually.It could be concluded that the order of resistance to drought was from Viburnum sargentii Koehne to Spiraea cantoniensis Lour and to Callicarpa dichotoma Lour.