干旱胁迫对俄罗斯大果沙棘幼苗光合荧光参数的影响

Effects of Drought Stress on Photosynthetic Fluorescence Parameters of Hippophae rhamnoides ssp.Russia Seedlings

以二年生俄罗斯大果沙棘实生苗为试材,采用室内盆栽控水试验法,设置对照(CK)、轻度(LS)、中度(MS)和重度(SS)4个干旱胁迫水平,研究了干旱胁迫对俄罗斯大果沙棘光合特性的影响,以期为规范其栽培技术和合理的发展规模提供参考依据。结果表明:1)随干旱胁迫程度加深和时间延长,俄罗斯大果沙棘的净光合速率、蒸腾速率和气孔导度逐渐减小,胞间CO_(2)浓度均呈先增加后减小的变化规律,但水分利用效率逐渐增加,而CK各指标无明显变化,SS与LS和MS之间有显著差异。2)随胁迫程度加深和时间延长,PSⅡ潜在活性、PSⅡ最大的光化学量子产量、光化学淬灭系数、非光化学淬灭系数、表观光合电子传递效率和PSⅡ实际光化学量子产量均有逐渐减小的变化趋势,而CK胁迫下4个荧光参数指标均无明显变化。3)MS和SS干旱胁迫处理下俄罗斯大果沙棘的光合、蒸腾与气孔导度密切相关。MS胁迫处理下光合、蒸腾、气孔导度与荧光参数各指标也有显著相关性。

Taking the biennial Hippophae rhamnoides ssp.Russia seedlings as the test materials,the indoor potted water control test method was used,and four drought stress levels of contrast(CK),light(LS),moderate(MS)and severe(SS)were set.The effects of drought stress on the photosynthetic characteristics of Hippophae rhamnoides ssp.Russia were studied,in order to provide reference for its standardized cultivation technology and reasonable development scale.The results showed that with the increasing of drought stress and the extension of drought stress time,the net photosynthetic rate,transpiration rate and stomatal conductance of Hippophae rhamnoides ssp.Russia decreased gradually,and the water use efficiency increased gradually,and their intercellular CO_(2)concentration increased first and then decreased.However,the water use efficiency gradually increased,while CK indicators did not change significantly,and there was a significant difference between SS and LS and MS.Under drought stress(LS,MS and SS),the potential activity of PSⅡ,the maximum photochemical quantum yield of PSⅡ,the photochemical quenching coefficient,the nonphotochemical quenching coefficient,the apparent photosynthetic electron transfer efficiency and the actual photochemical quantum yield of PSⅡdecreased gradually with the increasing of drought stress and the extension of drought stress time,and there was no significant change for the four fluorescence parameters of CK treatment.Photosynthesis,transpiration and stomatal conductance of Hippophae rhamnoides ssp.Russia under MS and SS drought stress were closely related.Photosynthesis,transpiration,stomatal conductance and fluorescence parameters were also significantly correlated under MS stress.