干旱胁迫对欧李幼苗表型可塑性的影响

Effects of drought stress on phenotypic plasticity of Cerasus humilis

关键词:  欧李, 干旱胁迫, 表型可塑性

Key words:   Cerasus humilis, drought stress, phenotypic plasticity

摘要:

该研究以欧李为材料,探讨了干旱胁迫对欧李表型可塑性的影响。结果表明:(1)随着干旱胁迫的加剧,欧李根生物量、枝叶生物量、植株总生物量积累、根冠比和根冠比胁迫指数均呈现先升高后降低的趋势,在T1处理下达到最大值,并显著高于其他处理(α=0.05)。(2)随土壤含水量的降低,欧李根的生物量分配指数呈现先增加后降低的趋势,叶生物量与之相反,在T1处理下根的生物量分配指数最大,枝叶的最小(α=0.05)。(3)在水分供应为60%～80%时,欧李的株高、冠幅、基径、二级分枝数、主根长、主根直径及侧根数量均达到最大值(α=0.05),对一级分枝数的生长没有显著影响。(4)随着水分胁迫的加剧,叶片长从T2处理开始下降,叶片宽、单片叶面积及比叶面积均呈现先增加后减少的趋势(α=0.05)。综上可得,欧李通过调整形态特性和各器官生物量积累及其分配对不同干旱胁迫条件产生了较强的可塑性。

Abstract:

In order to study the phenotypic plasticity of Cerasus humilis, the growth characteristics and morphology cha-racteristics of C. humilis were studied under the different drought stresses. The main results are as follows:(1)Under drought stress condition, the growth characteristics of C. humilis was significantly affected. With the increase of drought stress, the biomass, leaf biomass, total biomass accumulation, root-to-root ratio and root-to-shoot stress ratio increased first and then decreased, and reached the maximum under T1 treatment, which was significantly higher than those under other treatments.(2)With the decrease of soil water content, the biomass distribution index of C. humilis increased first and then decreased. On the contrary, the biomass distribution index of root and leaf was the smallest under T1 treatment.(3)When the water supply was between 60% and 80%, the plant height, crown width, diameter, secondary branch number, main root length, root diameter and lateral root number of C. humilis were the highest, and there was no significant effect on the growth of primary branches.(4)With the increase of drought stress, leaf length decreased from T2 treatment, leaf width, leaf area and specific leaf area increased first and then decreased. Therefore, the phenotypic plasticity of adjusted the morphological characteristics and the distribution of organ biomass were greater under the diffe-rent drought stresses.