【摘要】 对不同水分条件下小麦叶片叶绿素含量、叶绿素荧光参数及光合速率的变化进行了研究,结果表明,随着胁迫的加剧,其叶绿素含量降低,且叶绿素a的含量下降比叶绿素b的含量要快.在不同水分条件下,叶片叶绿素含量及光合速率随生育进程的变化趋势基本一致,拔节期到抽穗期迅速上升,灌浆期后迅速下降,且叶绿素含量与光合速率呈显著的正相关.在水分胁迫下旗叶的T1 /2 值减少,旗叶光系统II PSII 原初光能转化效率 Fv/Fm 和潜在活性 Fv/Fo 降低,胁迫程度越大其值降低幅度越大,轻度胁迫与对照相比其值降低幅度小,而重度胁迫其值急剧下降,这些值的降低,导致了光合作用的潜在活力降低,影响了光合电子的传递和CO2 同化的正常进行,最终导致产量降低.更多还原

【Abstract】 Under different water conditions,the chlorophyll contents,chlorophyll fluorescent parameters and photosynthetic rates of wheat leaves were studied,which indicated that the chlorophyll content decreased with intensified water stress and that the contents of chlorophyll a decreased more quickly than that of chlorophyll b.Under same water conditions,the chlorophyll conents and photosynthetic rates varied in similar seasonal patterns,i.e.quickly rising from the jointing to the heading and quickly decreasing at late kernel-filling stage,whereas they showed a significant positive correlation.Water stress made the T 1/2 of the flag leaves,and the Fv/Fm and Fv/Fo of flag-leaf PSⅡ decrease and intensified water stress increased their decrements;Light water stress made these values decrease within a small range and strong water stress make these values decreased with a large range,compared with those of the control.These decrements resulted in decreased potential photosynthetic capabilities thus affecting photosynthetic eclectron transport and CO₂ assimilation,and then leading to decreased wheat yield.更多还原