濕地植物根系泌氧的特征

研究了10種濕地植物的根系泌氧（radial oxygen loss, ROL）特征及其相關因素。泌氧不僅在物種間存在差異，而且在根系的不同部位也有明顯不同。根據泌氧速率在根不同部位的變化趨勢可將濕地植物的根部泌氧方式分為3種類型。類型Ⅰ為ROL在根的任意部位均較高，且沿氧傳輸方向逐漸降低；類型Ⅱ為ROL在根尖區域最高,之后沿根基部方向迅速降低；類型Ⅲ為ROL在根的任何位置泌氧速率非常低，且不隨根的部位而變化.溶液培養條件下，缺氧脅迫能使植物根的直徑增粗，根孔隙度提高，通氣組織更加發達，誘導根基部泌氧屏障的生成，使泌氧速率和泌氧方式發生變化。

Characteristics of radial oxygen loss (ROL) from root of 10 wetland plants was studied in this paper. Root ROL varied with the distance from root tips, as well as with species. Spatial pattern of ROL was identified to show 3 types according to the trends of ROL rate along adventitious roots .Type I showed a relatively high rate of ROL along the whole root, declining gradually from root apex to root basal part. Type II was indicated by significantly high ROL in root apex but decreased greatly towards root base. As for Type III, ROL was similar but very low along the whole root. In nutrient solutions, deoxygenation caused a series of changes in root anatomy of some species, such as increased root diameter, root porosity and more developed aerenchyma, inducing a ROL barrier in root basal part and the consequent change of ROL profile.Copyright © 2007 華東師范大學.