中文摘要：

为探讨油菜光合机构对干旱胁迫的响应,研究了2个抗旱性不同的油菜（Brassica napus L.）品种在干旱胁迫下农艺性状、气体交换参数、叶绿素荧光参数、叶绿体超微结构及Rubisco活性等指标的变化。结果表明,干旱胁迫下,相对增长率、总干重、叶面积和叶片相对含水量降低,而根冠比增加;净光合速率、蒸腾速率、气孔导度和胞间CO2浓度降低,而气孔限制值增加;PSⅡ最大光能转换效率、PSⅡ实际光能转换效率、光化学淬灭和电子传递效率降低,而非光化学淬灭系数增加;两品种的叶绿体超微结构遭到不同程度破坏;且叶绿素含量和Rubisco活性降低,脯氨酸和可溶性糖的含量增加。敏感型品种秦优8号光合机构遭受干旱的破坏程度明显大于抗旱型品种Q2。

英文摘要：

To better understand the response of photosynthetic apparatus in rapeseed to drought stress, 2 different drought resistance rapeseed （Brassica napus L.） cultivars Qinyou 8 （drought sensitive） and Q2 （drought tolerant） were planted in pots under movable rain-shelter with different drought treatments （well-watered and drought stress）. Drought effects on agronomic traits, gas exchange parameters, chlorophyll fluorescence parameters, chlorophyll ultrastructure and rubisco activity were studied. Results showed that relative growth rate, total biomass, leaf area and leaf relative water content decreased under drought in both genotypes. Root shoot ratio was increased. Among the parameters, net photosynthetic rate, transpiration rate, stomatal conductance and intercellular CO2 concentration decreased, but stomatal limitation was increased. Variable and maximum fluorescence （Fv/Fm）, effective quantum yield of PSII, photochemical quenching coefficient and electron transport rate decreased under drought, but non-photochemical quenching increased. Chlorophyll ultrastructures of both cultivars were damaged. Their chlorophyll content and rubisco activity decreased, but proline and soluble sugar contents increased. Drought damage on Qinyou 8 was worse than that on Q2.