现蕾期干旱胁迫对烟草光合与抗氧化特性的影响

为明确不同烟草品种对现蕾期干旱胁迫的响应,以NC89和云烟97为材料,通过盆栽试验,在现蕾期进行干旱胁迫,分析不同处理光合指标、抗氧化酶(SOD、POD)活性和叶绿素、蛋白质、丙二醛(MDA)、脯氨酸(Pro)、谷胱甘肽(GSH)含量等指标变化。结果显示,干旱胁迫下,各指标较对照变化大,但仅叶绿素和Pro含量两个品种处理间均达到显著水平,MDA含量仅NC89达到显著水平,GSH含量仅云烟97达到显著水平。可见,现蕾期干旱胁迫下,烟草的蒸腾速率、气孔导度、净光合速率降低,胞间CO2摩尔分数先降后升,SOD活性、叶绿素、蛋白质、Pro含量上升,而POD活性、MDA、GSH含量在不同烟草品种上响应不同。总体来讲,NC89现蕾期抗旱性高于云烟97。

Effects of Drought Stress on Photosynthesis and Antioxidant Properties of Tobacco in Budding Stage

In order to study the response of different tobacco cultivars to drought stress, NC89 and Yunyan 97(YY 97) were used as the plant material to analyze the physiological and biochemical changes of photosynthetic indicators and antioxidant enzyme (SOD, POD) activities and the content of chlorophyll, protein, MDA, Pro, GSH through pot experiment under two kinds of drought stress treatments in the budding stage. The results showed that under drought stress, each index changed greatly, but only the chlorophyll and Pro content, and the MDA content of NC89, GSH content of YY97 reached the significant difference level. The transpiration rate, stomatal conductance and net photosynthetic rate of tobacco decreased; intercellular CO₂ concentration decreased firstly and then increased; SOD activity, chlorophyll, protein and Pro content, increased; POD activity, MDA and GSH content showed different responses in different tobacco cultivars. As a conclusion, NC89 was more drought resistant than YY97.