Effects of High Temperature on Chlorophyll Fluorescence,Active Oxygen Resistance Activity,and Grain Quality in Grain-Filling Periods in Rice Plants
Effects of High Temperature on Chlorophyll Fluorescence,Active Oxygen Resistance Activity,and Grain Quality in Grain-Filling Periods in Rice Plants
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DOI：
10.3724/sp.j.1006.2008.01662
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
T. Zhong
中科院分区：
文献类型：
--
作者：
T. Zhong
淀粉、蛋白质、脂类等同化物的合成依赖于光合作用。在胁迫下，与光合作用有关的色素、初级反应和电子传递链受到伤害或抑制。由“温室效应”引起的高温影响越来越频繁。高温胁迫下光合作用的原初反应被抑制, 抗活性氧活力降低, 水稻叶片功能期缩短, 可能是稻米品质降低的重要原因。结果表明：在高温（33℃）下，叶片叶绿素含量下降，初始荧光（Fo）明显增加，PS Ⅱ最大光化学效率（Fv/Fm）和PS Ⅱ潜在光化学效率（Fv/Fo）下降，Fv/Fo和Fv/Fm在整个灌浆期下降较快，尤以灌浆后期下降最为明显。灌浆后期抗活性氧活性（AORA）分别比对照降低45.16%和35.99%;高温条件下，两品种籽粒总淀粉和直链淀粉含量均低于对照，蛋白质含量有不同程度的增加，垩白度和千粒重变化显著。高温胁迫下稻米品质退化的主要原因与水稻叶片光合初级反应受到抑制、抗活性氧活性下降和功能期缩短有关。
The synthesis of assimilate such as starch,protein and lipid depends on the photosynthesis. Under stresses,the pigments,primary reaction and electronic transport chain which have relations with photosynthesis are hurt or inhibited. The effect of high temperature caused by "Greenhouse Effects" becomes more and more frequent. To elucidate the injury mechanism under high temperature in rice plants,the dynamic changes of chlorophyll content,chlorophyll fluorescence parameters and active oxygen resistance activity were measured and the grain quality indices including starch,protein,and chalkiness were also analyzed in rice plants of cultivars Xinongyou 30 and Fuyou 1 during grain-filling period under high temperature treatment in climatic cabinets. The results showed that under high temperature(33℃ ),chlorophyll content of leaves decreased,initial fluorescence(Fo) increased obviously,maximal photochemical efficiency of PS II(Fv/Fm) and the potential photochemical efficiency of PS II(Fv/Fo) decreased,Fv/Fo and Fv/Fm declined faster during the whole grain-filling period,especially in late period. Meanwhile,active oxygen resistance activity(AORA) lowered by 45.16 and 35.99% as compared with the control in the late grain-filling period;under high temperature condition,the total starch and amylose contents of grains were lower than those of control,the protein contents increased to a different degree,and chalkiness and 1000-grain weight changed significantly in two cultivars. The main reason of degeneration of grain quality under high temperature stress is related to the inhibition of primary reaction of photosynthesis,drop of active oxygen resistance activity and contraction of functional period in leaves of rice plants.