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以一年生红叶石楠‘鲁班’盆栽苗为材料,研究了不同浓度NaCl胁迫下其生长、生理生化指标和叶片显微结构的变化。结果表明:在0.2%、0.4%和0.6%的NaCl胁迫下植株生长正常,而在0.8%、1.0%和1.2%的NaCl胁迫下植株生长受抑制;叶片最大荧光(Fm)、光系统II(PSII)最初光能转换效率(Fv/Fm)、光化学猝灭系数(qP)、表观光合电子传递速率(ETR)随NaCl浓度的升高而降低,其中在0.8%、1.0%和1.2%的NaCl胁迫下比对照显著降低;叶绿素a和叶绿素b含量及叶绿素a/b的比值随盐浓度的升高而降低;在0.2%、0.4%和0.6%的NaCl胁迫下,叶片中超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)的活性较对照显著上升,而当NaCl浓度为0.8%、1.0%和1.2%时显著下降;在0.4%和0.6%的NaCl胁迫下叶片中丙二醛(MDA)的含量与对照相比显著降低,0.8%、1.0%和1.2%的NaCl胁迫下显著升高;叶中栅栏细胞在NaCl浓度为0.2%、0.4%和0.6%时逐渐纵向伸长且排列更紧密,浓度为0.8%、1.0%和1.2%时逐渐缩短且疏松,且栅栏组织厚度在0.6%的NaCl胁迫下达到最大。由此表明,红叶石楠‘鲁班’在NaCl浓度不高于0.6%的基质中能正常生长。
The growth, physiological and biochemical indexes and the changes of the leaf microstructures of annual potted seedlings of ’Hongban’ were studied under different NaCl concentrations. The results showed that the plants grew normally under NaCl stress of 0.2%, 0.4% and 0.6%, while the growth of plants was inhibited under the NaCl stress of 0.8%, 1.0% and 1.2%. The maximum fluorescence (Fm), photosystem II (Fv / Fm), the photochemical quenching coefficient (qP) and the photosynthetic electron transfer rate (ETR) of PSII decreased with the increase of NaCl concentration, and the highest photosynthetic rate of 0.8%, 1.0% and 1.2% The content of chlorophyll a and chlorophyll b and the ratio of chlorophyll a / b decreased with the increase of salt concentration under NaCl stress. Under the NaCl stress of 0.2%, 0.4% and 0.6%, the content of superoxide dismutase The activities of SOD, POD and CAT increased significantly compared with the control, but decreased significantly when the NaCl concentrations were 0.8%, 1.0% and 1.2%, while those between 0.4% and 0.6% The content of malondialdehyde (MDA) in leaves of the leaves under NaCl stress was significantly lower than that of the control (0.8%, 1.0% and 1.2% NaCl), and the contents of NaCl in the leaves were 0.2% and 0.4% respectively 0.6%, they gradually grew longitudinally and arranged more closely. When the concentrations were 0.8%, 1.0% and 1.2%, they gradually shortened and became loose, and the thickness of palisade tissue reached the maximum under 0.6% NaCl stress. This shows that Photinia ’Luban’ grows normally in a substrate with a NaCl concentration of not more than 0.6%.