盐胁迫对四园林绿化树种叶片中叶绿素含量动态变化的影响

THE EFFECTS OF SALT STRESS ON THE CONTENTS OF CHLOROPHYLL IN SEEDLING LEAVES OF FOUR GARDEN TREE SPECIES

用不同浓度NaCl溶液处理一年生苗木乌桕(Sapiumsebiferum(L.)Roxb)、栾树(KoelreuteriapaniculataLaxm.)、黄栌(PistaciachinensisBunge.)、法桐(PlatanusorientalisL.),研究了四园林绿化树种叶片中叶绿素a、叶绿素b和总叶绿素含量的动态变化以及叶绿素与丙二醛、脯氨酸的相关性。结果表明,叶绿素a和总叶绿素含量均随盐胁迫程度的增加而降低,但叶绿素a和b降解的幅度以及叶绿素a/b值并不呈现单一的变化趋势。相关分析表明,四树种总叶绿素含量与膜脂过氧化产物丙二醛含量负相关,说明盐胁迫下叶绿素的降解与膜脂过氧化存在着密切的关系。乌桕、栾树叶片中Chl与Pro含量呈正相关;而法桐、黄栌则负相关。游离Pro的积累对叶绿素的合成与降解并未起直接作用。

The one-year old poted seedlings Sapium sebiferum(L.) Roxb., Koelreuteria paniculata Laxm ,Pistacia chinensis Bunge.and Platanus orientalis L. were tested by applying 0.0%,0.2%,0.4%,0.6% NaCl solutions. The dynamic changes of a, b and total contents of chlorophyll were studied and the correlation of chlorophyll contents with MDA and Pro were analysed. The results show that both of the chlorophyll a and total chlorophyll contents are decreased as the increase of the salt concentrations. Chlorophyll a and b were quickly decomposed, but the decomposing rate and the a/b values are not consistent. Correlation analysis indicates that total chlorophyll contents were negatively correlated with MDA contents, showing that the deduction of chlorophyll under salt stress was closely related to the process of lipid over-oxidation. The total chlorophyll contents in seedling leaves of Sapium sebiferum(L.) Roxb.and Koelreuteria paniculata Laxm were positively correlated with Pro contents. However, the correlation was negative in that of Pistacia chinensis Bunge and Platanus orientalis L.. The accumulation of free-Pro in leaves did not directly affect the metabolism of chlorophll.