一种定量测定水稻根系氧化力的新方法

A Novel Method for Quantifying Oxidizing Capacity of Rice (Oryza sativa L.) Roots

根系氧化力大小与根表铁膜数量密切相关,铁膜以Fe3+形态为主。本文根据水稻根表铁膜数量,探讨了一种测定水稻根系氧化力的新方法。首先,在水稻根系所在溶液中加入定量硫酸亚铁(Fe2+),处理1天后,水稻根系将一部分Fe2+氧化成Fe3+,剩余Fe2+用H2O2滴定,得滴定值A。然后,用H2O2滴定没有种植水稻的硫酸亚铁溶液,得滴定值B。根据不种植与种植水稻H2O2的消耗量,滴定值之差(B-A),即为水稻根系氧化力。该方法要求Fe2+浓度大于0.8 mmol/L,过氧化氢消耗量与Fe2+浓度成正比(R2=0.999 2)。测定过程中,应先加显色剂邻菲罗啉,然后加入磷酸。该方法在不损伤水稻根系情况下可定量测定水稻根系氧化力。

Root oxidizing ability is the requisite for the iron plaque. Therefore, according to the quantity of iron formation of iron plaque on roots surface. Fe^3＋ is a major form in the plaque on roots surface, this paper explored a novel method for quantifying the oxidizing capacity of rice roots. First of all, added quantitative ferrous sulfate （Fe^2＋） into the culture solution, rice roots would oxidized parts of Fe^2＋ to Fe^3＋ after 1 d, remaining Fe^2＋ in the culture solution was titrated with H2O2, the titration value was A. Then, H2O2 titrated Fe^2＋ of culture solution without cultivation rice seedlings, the titration value was B. The difference of H2O2 titration value （B-A） was named Root oxidizing ability. This method required： Fe^2＋ concentration was more than 0.8 mmol/L, H2O2 consumption was proportional to Fe^2＋ （R^2 = 0.999 2）. During the determining process, the culture solution was added 1, 10-Phenanthroline monohydrate as colour-display reagent firstly, then added phosphoric acid. This method could quantitatively determine oxidizing capacity of rice roots which were not damaged.