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为了解植物干旱生理适应机制和恢复机制,以梨品种‘翠冠’和‘黄冠’幼树为试材,研究土壤干旱胁迫及复水条件下叶片光合参数、叶片相对含水量、叶片质膜透性、超氧化物歧化酶活性及脯氨酸含量的变化特性.结果显示:1)随着干旱胁迫的加剧,两品种的叶片净光合速率、气孔导度和蒸腾速率均呈下降趋势;‘翠冠’叶片胞间CO2浓度呈先降后升的趋势,而‘黄冠’呈持续下降趋势,但‘黄冠’光合作用的4项指标明显高于‘翠冠’;复水后,两品种的光合指标恢复显著,但均未超过对照水平.2)干旱胁迫引起两品种的叶片相对含水量急剧下降,叶片质膜透性和脯氨酸含量显著升高,超氧化物歧化酶活性呈先升后降趋势;复水后,两品种的4项指标不同程度地得以恢复,但大部分指标没有恢复到对照水平,其中‘黄冠’各项指标在复水前后的变化幅度比‘翠冠’更小.综合分析表明,‘翠冠’和‘黄冠’对干旱胁迫的响应存在差异,‘黄冠’对干旱逆境具有更强的适应能力.
In order to understand the mechanism of physiological adaptation and restoration of plant drought, the pear varieties ’Cuiguan’ and ’Huangguan’ saplings were used to study the effects of soil drought stress and rehydration conditions on leaf photosynthetic parameters, leaf relative water content, Permeability, superoxide dismutase activity and proline content were studied.The results showed that: 1) With the aggravation of drought stress, the net photosynthetic rate, stomata conductance and transpiration rate of two cultivars all showed a decreasing trend; Cucumber crown ’leaf intercellular CO2 concentration showed a downward trend and a downward trend, while’ Huangguan ’showed a continuous downward trend, but the four indicators of’ Huangguan ’photosynthesis were significantly higher than that of’ Cui Guan ’ The photosynthetic indexes of the cultivars recovered significantly, but none of them exceeded the control level.2) The relative water content of the leaves of two cultivars decreased sharply under drought stress, the plasma membrane permeability and proline content of leaves increased significantly, and the activity of superoxide dismutase After rewatering, the four indicators of the two varieties recovered to varying degrees, but most of the indicators did not return to the control level, and the change of each index of ’Huangguan’ before and after rewatering was more than that of ’Cui Crown ’smaller. Comprehensive points The results showed that the responses of ’Cui Guan’ and ’Huang Guan’ to drought stress were different, and ’Huang Guan’ had more adaptability to drought stress.