中文摘要：

通过对叶绿素含量及叶绿素荧光参数的测定和分析,研究了干旱和低磷胁迫对油菜不同生育期叶片叶绿素荧光特性的影响。结果表明：与对照相比,油菜在蕾苔期和花期受到干旱和低磷胁迫后,叶绿素含量、最大荧光（Fm）、PSⅡ最大的光化学量子产量（Fv/Fm）、PSⅡ实际的光化学量子产量（ΦPSⅡ）、光化学淬灭系数（qP）、表观光合电子传递速率（ETR）显著降低,初始荧光（Fo）、非光化学淬灭系数（NPQ）则显著上升,但在苗期却没有显著的变化。表明油菜在蕾苔期和花期遭受到干旱和低磷胁迫后,油菜叶片PSⅡ反应中心受到损伤,光合电子传递过程受到抑制;这些参数在蕾苔期由低磷胁迫引起的变化幅度明显大于由干旱胁迫引起的变化幅度,在花期则相反。蕾苔期是低磷胁迫对油菜造成光抑制影响最大的时期,而花期则是干旱胁迫对油菜造成光抑制影响最大的时期。

英文摘要：

The chlorophyll content and chlorophyll fluorescence parameters were measured to explore the effects of drought and phosphorus deficiency on characteristics of chlorophyll parameters in leaves of rapeseed during different growing stages.The results showed that,under drought and phosphorus deficiency during the stem elongation and flowering stage,the content of chlorophyll,maximum fluorescence（Fm）,PSⅡmaximum quantum yield（Fv/Fm）,PSⅡ actual quantum yield（ΦPSⅡ）,photochemical quenching coefficient（qP） and apparent photosynthetic electron transport rate（ETR） were obviously decreased,while the initial fluorescence（Fo） and non-photochemical quenching coefficient（NPQ） were obviously increased.But these parameters did not obviously change during the seedling stage.Therefore,under drought and phosphorus deficiency during the stem elongation and flowering stage,the PSⅡ reaction center in leaves of rapeseed was damaged and the process of photosynthetic electron transport was restrained.Furthermore,the change extent of these parameters that was caused by phosphorus deficiency was greater than that was caused by drought stress during the stem elongation stage,but it was opposite during the flowering stage.The period during which the maximal effect of photoinhibition was caused by phosphorus deficiency was the stem elongation stage,but that by drought stress was the flowering stage.