叶面施磷对蓖麻生长、镉积累及亚细胞分布的影响

Effects of P Foliar Spraying on Plant Growth,Cd Accumulation and Subcellular Distribution in Ricinus Communis

采用营养液培养试验，研究了在不同浓度镉（50、100和150μmol·L^-1）胁迫下，叶面喷施0．4％磷肥对蓖麻生理特性、镉积累及亚细胞分布的影响。结果表明，与未施磷处理相比，叶面施磷使蓖麻根、茎、叶生物量分别增加了23．2％～61．5％、31．2％～68．3％和14．7％～23．6％，叶绿素a、叶绿素b和类胡萝卜素含量分别增长了6．8％～78．0％、10．1％～84．1％和30．0％～52．1％。与未施磷处理相比，叶面施磷使根系中镉含量增大了25．0％～59．6％，显著提高了地下部对镉的积累量，茎、叶中镉含量无显著变化；根、茎、叶中细胞壁中镉含量的分配比例显著增大，而细胞器分配比例则相对减少。可见，叶面施磷提高了植株细胞壁对镉的固持作用，降低了镉的迁移能力和生理毒性。

A hydroponic experiment was conducted to investigate the influence of foliar spraying of 0.4% phosphate fertilizer （P） on the physiological parameters, Cd accumulation and subcellular distribution characteristics in energy crop Ricinus communis with different Cd doses （50,100,150μmol·L^-1 ）. The re- sults showed that P spraying increases plant dry mass by 23.2%-61.5%, 31.2%-68.3% and 14.7%- 23.6% in the roots, stems and leaves, respectively, and the chlorphyll a, chlorphyll b and carotenoid con- tents were increased by 6.8%-78.0%, 10.1%-84.1% and 30.0%-52.1%, respectively. Foliar spra- ying of P significantly increased Cd concentration in the roots by 25.0%- 59.6%, but Cd contents in shoots and leaves showed no significant difference. The proportions of Cd in the cell wall increased, while that in cell organelle decreased. It is supposed that P addition can strengthen cell wall binding, so as to limit Cd translocation and reduce its physiological toxicity in plants.