探讨香蒲Typha orientalis不同部位水浸提液对黄菖蒲Iris pseudacorus,苦草Vallisneria natans,荇菜Nymphoides peltatum和芦苇Phragmites australis等4种水生植物化感效应和作用规律.采用室内离体生测法,研究0.5,5.0和50.0 g·L-13个质量浓度梯度的香蒲根、 叶和蒲黄浸提液对4种水生植物种子发芽率及幼苗的生长影响,并对受抑制作用最强的黄菖蒲幼苗测定其丙二醛(MDA)和超氧化物歧化酶(SOD)活性.结果表明:香蒲各部位浸提液对4种植物的发芽率、 幼芽和幼根的生长均有显著(P<0.05)的化感抑制作用,总体趋势表现出低促高抑的双重质量浓度效应;不同部位浸提液对4种水生植物的抑制作用强弱顺序为叶浸提液>蒲黄浸提液>根浸提液,且对幼根生长的影响大于幼芽;3种浸提液处理下,黄菖蒲幼苗体内MDA随浸提液质量浓度的升高而增大,SOD均表现出先升高后下降的趋势.香蒲水浸提液通过对水生植物种子的化感效应,引起细胞的膜脂过氧化加剧,抗氧化酶系统受到损伤,从而抑制水生植物种子的萌发和幼苗的生长,叶片是香蒲主要的化感作用部位.%This study was conducted to explore the allelopathic the law of action for aquatic extracts using dif-ferent organs of Typha orientalis and the effect on seeds of four species of hydrophytes: Iris pseudacorus, Val-lisneria natans, Nymphoides peltatum, and Phragmites australis. The petri-dish cultivation method was used to determine the influence on germination and growth of the radicle and seedling using three different concentra-tions including 0.5 g·L-1, 5.0 g·L-1 and 50.0 g·L-1 of root, leaf, and pollen extracts on the four prepared seeds. In addition, the activities of malondialdehyde (MDA) and superoxide dismutase (SOD) for I. pseudacorus were measured. Results showed that root, leaf, and pollen extracts of T. orientalis had strong effects on germination and seedling growth. Overall, low concentrations promoted and high concentrations inhibited with inhibition be-ing in the order of leaf extract > pollen extract > root extract and with the effect on the radicle being greater than the seedling. For three aquatic extracts, MDA activity of Iris pseudacorus increased with the extract con-centration; whereas, SOD activity showed an 'up-down' pattern. Thus, the effects of T. orientalis aqueous extracts on seeds of aquatic plants caused membrane lipid peroxidation and destroyed antioxidant enzyme sys-tems which eventually affected the germination and growth of seedlings; meanwhile, leaves were the main organ causing allelopathic effects.
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