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以田间8年生沙地云杉为试验材料,研究干旱胁迫对沙地云杉的光合、叶绿素荧光参数的影响,为沙地云杉在干旱荒漠区的推广应用等方面提供理论依据。结果表明:(1)随着干旱胁迫加剧,沙地云杉的光合参数净光合速率(Pn)、气孔导度(Gs)、胞间C02浓度(Ci)和蒸腾速率(Tr)也随之降低,当土壤含水量为17%时,净光合速率(Pn)最大。胞间C02浓度(Ci)和气孔导度(Gs)同时降低,说明气孔因素是导致沙地云杉叶片净光合速率下降的主要因素。(2)干旱胁迫对沙地云杉叶绿素荧光参数均产生显著影响,其中最大光化学效率PSII(Fv/Fm)、实际光化学效率(ΦPSⅡ)、表观光合电子传递速率(ETR)对干旱胁迫的反应较为敏感,可作为评价沙地云杉抗旱能力的参考指标。综合分析各项指标表明,干旱胁迫对沙地云杉的光合荧光特性影响显著,气孔因素是导致沙地云杉叶片净光合速率下降的主要因素。
The experiment was conducted to study the effects of drought stress on the photosynthetic and chlorophyll fluorescence parameters of 8-year-old sandy spruce from the fields in order to provide a theoretical basis for the promotion and application of sandy spruce in the arid and desert regions. The results showed as follows: (1) Pn, Gs, Ci and Tr decreased with the aggravation of drought stress When the soil water content was 17%, the net photosynthetic rate (Pn) was the largest. The intercellular C02 concentration (Ci) and stomatal conductance (Gs) decreased at the same time, which indicated that the stomatal factor was the main factor leading to the decrease of net photosynthetic rate in the spruce leaves. (2) Drought stress had a significant effect on the chlorophyll fluorescence parameters of the spruce (Picea sativa.), In which the maximum photochemical efficiency PSII (Fv / Fm), the actual photochemical efficiency (ΦPSⅡ) and the photosynthetic electron transport rate Is more sensitive and can be used as a reference index to evaluate drought resistance of Picea mongolica. Comprehensive analysis of the indicators showed that drought stress had significant effects on the photosynthetic fluorescence characteristics of Picea mongolica, and the stomatal factors were the main factors that led to the decrease of Pn in the leaves of Picea mongolica.