不同光温胁迫对成熟期烤烟光合生理特性的影响

Effects of light and temperature stress on photosynthesis of flue-cured tobacco at mature stage

为探究成熟期烤烟对环境胁迫的响应规律,以云烟87为供试材料,采用盆栽试验,模拟湖南烟区烤烟生育后期的高温强光胁迫,分析不同光温胁迫对成熟期烤烟光合生理特性的影响。结果表明:(1)随着光照强度的变化,常温下烟株蒸腾速率、气孔导度和净光合速率的变化明显,在80 000 lux处达到最大值;高温下烟株蒸腾速率、气孔导度和净光合速率则明显降低。(2)整体上,同等光强下,高温处理的烟株蒸腾速率、气孔导度和净光合速率呈下降趋势,胞间CO_2浓度升高。(3)高温强光胁迫下,成熟期烤烟的蒸腾速率、气孔导度和净光合速率均显著降低,胞间CO_2浓度升高,光合能力下降。(4)相关性分析表明,烤烟净光合速率与气孔导度呈极显著正相关,蒸腾速率与净光合速率、气孔导度呈显著正相关。

To investigate the effects of environmental stress on flue-cured tobacco at mature stage, a pot experiment using Yunyan 87 as an experimental leaf was conducted to simulate high temperature and high light intensity at late growth stages in Hunan tobacco-planting areas. The effects of light and temperature stress on the photosynthetic characteristic of Yunyan 87 at mature stage were analyzed. The results showed that： 1） With the variation in light intensity, the transpiration rate, stomatal conductance and net photosynthetic rate of the flue-cured tobacco differed significantly at normal temperature, and peaked at 80000 lux; while all of them significantly decreased at high temperature. 2） Generally, at the same light intensity, the transpiration rate, stomatal conductance and net photosynthetic rate of the tobacco decreased and intercellular CO2 concentration increased at high temperature. 3） Under high light and temperature stress, the transpiration rate, stomatal conductance and net photosynthetic rate significantly decreased, intercellular CO2 concentration Increased, and the photosynthetic capacity reduced. 4） Correlation analysis indicated that net photosynthetic rate significantly positively correlated to stomatal conductance of the flue-cured tobacco and transpiration rate positively correlated to net photosynthetic rate and stomatal conductance.