溶氧条件对美人蕉和风车草根系泌氧特征的影响

Effecs of Oxygenation on Radial Oxygen Loss Characteristics of Canna indica and Cyperus alternifolius

采用标准氧化染色法研究了美人蕉和风车草在水培畜禽废水自然、缺氧和好氧3种溶氧状态下根系径向泌氧(Radial oxygen loss,ROL)类型的变化和特征,采用显微镜明暗场观察了相应的根系横截面特征。结果发现美人蕉在3种溶氧状态下根系径向泌氧类型分别为均匀强泌氧、根尖强烈泌氧和不泌氧3种;风车草的径向泌氧类型则分别为仅根尖有极微弱的泌氧、除根尖和根基以外的部位均匀较强泌氧和不泌氧3种。水体缺氧时美人蕉和风车草通过氧化进入根际好氧微环境的有毒离子来应对缺氧胁迫,不同的是美人蕉主要发生在根尖区域,风车草主要发生在根尖和根基以外的区域。当水中溶氧浓度较高时,植物根系获取氧气的主要途径是从水中摄取;当溶氧浓度较低时,主要是从空气中获取。

Radial oxygen loss（ROL） types and characteristics of Canna indica and Cyperus alternifolius were obtained by using standard oxidized dye（methylene blue agar） method,the plants were under hydroponics in natural,anoxic,and aerobic swine waste water,respectively.The cross section characteristics of plant roots were observed by front stand fluorescence microscope.The results showed that the patterns of ROL changed with the variations of dissolved oxygen（DO） concentration.The oxygen loss of Canna indica was strong and even,strong in root tip and no oxygen loss happening according to those three different DO conditions,while for Cyperus alternifolius,oxygen loss was weak in root tip only,in the area except root tip and base and no oxygen loss happening,respectively.When it was anoxic in the swine waste water,both plants took oxidizing toxic ions coming into rhizosphere aerobic microsystem to coping with hypoxia,and it occurred in root tip zone for Canna indica and in the area except root tip and base.When the DO concentration was high,plants got oxygen from water,while plants got oxygen mainly from air when it was low.