不同水稻品种的光氧化差异及活性氧清除剂的效应

水稻群体上层叶片常处于光饱和点以上,易受光氧化伤害。而生育期间由于外界环境不断变化,常遭受诸如低温、高温、干旱、营养不足、连续阴雨后放晴、SO_2和NO_2污染等逆境协迫,加重光氧化伤害。近来的研究表明,水稻对光氧化的敏感性品种间存在显著差异。对一些敏感的品种使用活性氧清除剂,可不同程度地减轻光氧化伤害。本试验在对产量形成关键的生育后期,鉴定不同品种在不同环境下的光氧化表现。并对光氧化敏感的品种使用不同的活性氧清除剂,以探索防止和缓解光氧化伤害的育种和栽培途径。1 材料与方法选用亚优2号、汕优63等6个水稻品种进行盆栽,常规管理。在孕穗期取相同叶龄的功能叶按焦德茂等的方法进行光氧化鉴定。施氮水平设高氮和低

Varietal Differences of Photooxidation in Rice and Effects of Active Oxygen Scavengers

The difference of photooxidation in various rice varieties under condition of inducing photooxidation was studied. The results indicated that indica-japonica hybrid rice Yayou 2, japonica rice 02428 and Niujiaobiannuo were more tolerant to photooxidation than indica hybrid rice Shanyou 63 and indica rice 3037 and Mars. Under condition of inducing photooxidation chlorophyll (Chl) content and Chl a/b declined slower, and carotenoid (Car) content as endogenous active oxygen scavenger was higher, higher superoxide dismutase (SOD) activity was induced and lasted longer in tolerant varieties. Nitrogen deficit and shading treatment exacerbated the degradation of Chl and Chl content, and increased the photooxidation damage. The exogenous active oxygen scavengers i. e. ascorbate (ASC), 8- hydroxoy-quinoline (8-HQ) and mannitor (MT) keeped higher SOD activity, lowered the degradation of Chl content and Chl a/b and photooxidation damage under condition of inducing photooxidation.