磷对铝胁迫下尾巨桉生长生理方面的缓解作用1）

摘要

To verify the growth and physiological Feature of exogenous phosphorus on ameliorating aluminum toxicity in Eucalyp -tus, we planted E.urophylla×E.grandis DH32-29 in sand solutions, and then detected the root and above-ground bio-mass, photosynthetic pigments , and antioxidant physiological indexes .Al of 5 mmol · L-1 significantly inhibited the root and above-ground biomass and increased the root shoot ratio .Al of 5 mmol· L-1 significantly inhibited the leaf Chl a/b and the contents of leaf Chl a , Chl b and Car .Al stress significantly increased cell membrane permeability and MDA ( the prod-uct of plasmalemma peroxidation ) and free proline contents , decreased soluble sugar and soluble protein content in Euca-lyptus leaf.Exogenous P played an important role in formation and inhibit decomposition of photosynthetic pigments , main-taining cell membrane structure stability by regulating reactive oxygen metabolism under Al toxicity , thereby reducing the Al damage to Eucalyptus growth photosynthetic pigments and resistance physiology .P of 200μmol· L-1 was better in the relieve effect under Al stress .%实验以尾巨桉DH32－29（E．urophylla×E．rga ndis DH32－29）为实验材料，用沙培法研究外源磷（P）对铝胁迫下尾巨桉生长和生理方面的缓解作用。结果表明：（1）5 mmol· L－1铝显著抑制尾巨桉的根、茎、叶生物量，显著提高根冠比。（2）铝胁迫抑制叶片叶绿素a、叶绿素b和类胡萝卜素质量分数，降低ω（叶绿素a）／ω（叶绿素b）值。（3）铝胁迫下叶片细胞膜透性显著增大，膜脂过氧化的产物丙二醛显著增加，细胞可溶性糖和可溶性蛋白质量分数显著降低，游离脯氨酸质量分数显著增大。（4） P缓解铝胁迫对光合色素的影响以及调节活性氧代谢以维持细胞膜结构稳定，有效缓解铝胁迫对尾巨桉生长、光合色素以及抗性生理造成的伤害，磷铝互作有利于缓解铝胁迫，P施用浓度为200μmol· L－1时，缓解铝胁迫效果较好。