Abstract

The parameters of chlorophyll α rapid fluorescence were assessed in husked oats (A. sativa subsp. sativa) and naked oats (A. sativa subsp. nudisativa). The goal of the study was to identify differences between two subspecies of oats with respect to the control of primary energy storage processes under the influence of osmotic stress for the subsequent selection of parameters and oat-breeding strategies to increase photosynthetic productivity in early drought conditions. Plants were grown on a complete Knop’s nutrient solution; osmotic stress was created by 10% polyethylene glycol (PEG‑400), and osmotic pressure was 0.709 mPa. Fluorescence parameters were determined using a Fluor Pen FP 110/S fluorometer (Photon Systems Instruments, Czech Republic). The data was processed by principal component analysis. In husked genotypes, the four main factors were responsible for 94.2% (control) and 91.4% (stress) variability of the assessed parameters. In naked oats, three principal factors were found (90.5% of variability) in the absence of stress and four factors (97.1% variability) under stress conditions. The flows of trapped energy (TR₀/RC) and electronic transport (ET₀/RC) were controlled in naked oat by one and the same factor under stress and by two different factors in the absence of stress, whereas those in husked genotypes were by one factor in the absence of stress and by two different factors under stress. Osmotic stress led to passing the control over adsorbed (ABS/RC) and trapped (TR₀/RC) energy flows from one factor to two factors in husked oats but did not affect naked oats. The parameter of efficiency of electron transfer to the primary acceptors of photosystem I (δRE) was controlled by two different factors and enhanced their effect (factor loading from 0.564 to 0.74). Under stress, the δRE parameter weakened the effect of both factors in naked genotypes (factor loading –0.625 and ‒0.705) and reduced the effect of one factor and strengthened the second factor in husked genotypes (factor loading –0.552 and 0.687).

中文翻译：

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渗透胁迫下燕麦叶光系统II活性组织的变化

摘要

对去壳燕麦 ( A. sativa subsp. sativa ) 和裸燕麦 ( A. sativa subsp. nudisativa )的叶绿素 α 快速荧光参数进行了评估。该研究的目的是确定两个燕麦亚种在渗透胁迫影响下控制初级能量储存过程方面的差异，以便随后选择参数和燕麦育种策略，以提高早期干旱条件下的光合生产力。植物在完整的诺普营养液中生长；渗透压由10%聚乙二醇（PEG-400）产生，渗透压为0.709 mPa。使用 Fluor Pen FP 110/S 荧光计（Photon Systems Instruments，捷克共和国）测定荧光参数。数据通过主成分分析进行处理。在去壳基因型中，四个主要因素导致评估参数的 94.2%（对照）和 91.4%（胁迫）变异性。在裸燕麦中，在没有压力的情况下发现了三个主要因素（90.5％的变异性），在压力条件下发现了四个主要因素（97.1％的变异性）。裸燕麦中的捕获能量流 (TR ₀ /RC) 和电子传输 (ET ₀ /RC) 在胁迫下由一个相同的因素控制，在没有胁迫的情况下由两个不同的因素控制，而带壳基因型中的截留能量流 (TR 0 /RC) 和电子运输 (ET 0 /RC)在没有压力的情况下由一个因素影响，在压力下由两个不同的因素影响。渗透胁迫导致去壳燕麦对吸附 (ABS/RC) 和截留 (TR ₀ /RC) 能量流的控制从一个因素变为两个因素，但不影响裸燕麦。电子转移到光系统 I 主要受体的效率参数 (δRE) 由两个不同的因素控制，并增强了它们的效果（因子负载从 0.564 到 0.74）。在胁迫下，δRE参数削弱了裸基因型中两个因素的影响（因子负荷–0.625和-0.705），并降低了一个因素的影响并增强了去壳基因型中的第二个因素的影响（因子负荷–0.552和0.687）。