摘要
比较了我国不同地区的 6个高产水稻品种在生育后期 (抽穗—成熟 )自然条件下剑叶的叶绿素荧光参数和膜脂过氧化产物及叶绿素 (Chl)衰减的表现 ,结果表明 ,水稻剑叶在衰老过程中叶片的Fv/Fm逐渐下降 ,过剩的光能形成活性氧O2 ·-、H2 O2 和膜脂过氧化产物MDA的积累 ,导致叶绿素衰减 ,发生光氧化早衰。这种现象在品种间有明显差异 ,与耐光氧化的粳稻相比 ,对光氧化敏感的籼稻汕优 6 3剑叶的Fv/Fm明显下降 ,活性氧积累多 ,Chl急剧衰减而表现“黄化”早衰 ,影响水稻灌浆结实。籼稻易于早衰机理与灌浆期温光条件有关。在适温 (2 5℃以上 )晴天 ,PSⅡ反应中心表现可逆失活的动态变化 ,中午强光下籼稻PSⅡ功能有明显的下调和光抑制 ;在低温强光下PSⅡ遭受光破坏 ,表现早衰。这与PSⅡ
Using six high yield varities from different ecological districts in China, the parameters of Chl fluorescence, the performance of membrane lipid peroxidations and the reduction of Chl content in flag leaf under natural conditions at the later developmental stages (from heading stage to mature stage) are studied. The results showed that Fv/Fm decreased gradually. The excessive light energy led to the accumulation of active oxygen O 2 ·-, H 2O 2 and the product of membrane lipid peroxidation, MDA, which resulted in the reduction of Chl content and early aging due to photo oxidation during the course of senescence of flag leaf. This phenomenon varied obviously in rice varieties. When compared with japonica tolerant to photooxidation, Fv/Fm in Indica Shanyou63 susceptible to photoxidation decreased significantly. An increased accumulation of active oxygen and a sharp drop of Chl content resulted in 'yellowish' early aging and influenced the filling and setting of rice grain. The mechanism on early aging in indica was related to light and temperature conditions in filling stages. On a fine day (above 25℃), PSⅡreaction center exhibited a dynamic change on revisable inactivation. Under strong mid day light, PSⅡ function in indica exhibited obvious down regulation and photo inhibitions; under strong light with low temperature, PSⅡresulted in photo damage, showing early aging, which was related to the degradation of PSⅡ D1 protein and the inhibition of the endogeneous protecting system such as xanthophyll cycle and the enzymes of scavenging active oxygen. The results suggested that for a view of high yield breeding, on the basis of good type plant, giving consideration to the utilization of heterosis and resistance to ealy aging, selecting japonica or a sterile line with japonica genotype as maternal was a breeding strategy worthy of more attention.
出处
《中国农业科学》
CAS
CSCD
北大核心
2002年第5期487-492,共6页
Scientia Agricultura Sinica
基金
国家重点基础研究发展专项经费资助项目 (G19880 10 10 0 )
