混合盐碱胁迫对地被菊寒露红生长的影响

Effects of saline-alkali stress on growth of Chrysanthemum morifolium ‘Hanluhong'

关键词:  混合盐碱胁迫, 地被菊, 株高, 根长, 光合特性, 叶绿素荧光

Key words:  saline-alkali stress, Chrysanthemum morifolium, plant height, root length, photosynthetic characteristics, chlorophyll fluorescence

摘要:

该研究以地被菊寒露红(Chrysanthemum morifolium ‘Hanluhong')为材料,一方面研究混合盐碱胁迫对其生长的影响,另一方面通过模拟青铜峡盐碱胁迫程度,探讨其在青铜峡地区的适生性。设置3个pH梯度(7.0、8.0、9.0),在每个pH梯度下用NaCl、Na₂CO₃、NaHCO₃、Na₂SO₄配置不同浓度(0、0.2%、0.4%、0.6%、0.8%、1.0%)的混合液对地被菊植株进行胁迫处理,观察并测定不同胁迫条件下植株株高、根长、光合特性及叶绿素荧光参数的变化。结果表明:(1)长时间生长在高盐碱环境会使地被菊寒露红生长缓慢,光合作用参数和叶绿素荧光参数下降。(2)青铜峡实验模拟组(pH=8.0,盐浓度为0.4%)的植株株高、根长的伸长速度随胁迫时间的延长均呈先降低后升高的趋势; 同时植株的光合作用参数、叶绿素荧光参数有降低趋势,但荧光参数下降变化未达到显著水平。综合分析可得,高盐、高碱环境均不利于地被菊寒露红植株的生长发育。在青铜峡地区的盐碱胁迫强度下,地被菊寒露红具有一定的抗盐碱性,基本能够正常生长,可用于当地植被及生态环境修复和园林造景。

Abstract:

We studied effects of saline-alkali stress on growth of Chrysanthemum morifolium ‘Hanluhong' and growth adaptability by simulating the saline-alkali stress intensity of Qingtongxia area. Three pH gradients(7.0, 8.0, 9.0)were set up in the experiment. Under each pH gradient, two neutral salts(NaCl and Na₂SO₄)and two alkaline salts(Na₂CO₃ and NaHCO₃)were used to configure mixed solutions with different saline concentrations(0, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%). Plant height, root length, photosynthetic characteristics and chlorophyll fluorescence were measured after each treatment. The results were as follows:(1)High concentration salt solution and pH value resulted in the decrease of these growth indexes.(2)The elongation rates of plant height and root length decreased at first and then increased in the imitating group with pH 8.0 and 0.4% salt concentration. When the stress time extended, the photosynthesis parameters, the maximum photochemical efficiency and the potential photochemical activity of photosystem Ⅱ decreased, but there was no significant differences among these fluorescence parameters. Considering the data of plant height, root length, photosynthesis and chlorophyll fluorescence, we deem that high saline-alkali environment is not beneficial to the growth and development of C. morifolium ‘Hanluhong', but C. morifolium ‘Hanluhong' can normally grow under the saline-alkali stress in Qingtongxia area. Therefore, it could be used in vegetation and ecological environment restoration for its salt and alkaline resistance.