水分胁迫对烤烟生理特性和光谱特征的影响

为明确烤烟在不同水分条件下的生理生态响应,通过盆栽试验研究了水分胁迫和复水对烤烟生理特性和光谱特征的影响。结果表明:干旱胁迫下烤烟叶片叶绿素和可溶性蛋白质发生降解,光合速率和蒸腾速率下降,导致干物质积累量降低;干旱胁迫后复水叶片光合速率和蒸腾速率有所回升,表现出一定的补偿效应。渍水胁迫亦严重影响烤烟叶片生理功能,造成叶片膜质过氧化程度加重,其危害程度甚至大于干旱胁迫。干旱和渍水胁迫均提高了可见光460～670 nm范围内的植株光谱反射率,而降低了近红外780～1050 nm范围内的光谱反射率。因此,光谱特征可作为诊断烤烟水分胁迫程度的重要手段。

Effects of Water Stress on Physiological and Spectral Characteristics of Flue-cured Tobacco

In order to investigate the physiological response of flue-cured tobacco to different watering conditions,the effects of water stress and water compensation on physiological characters and spectral features of flue-cured tobacco were studied with a pot culture experiment.The results showed that: 1) Under drought stress,chlorophyll and soluble protein in leaves degraded,and the photosynthetic rate and transpiration rate decreased,which resulted in the reduction of dry matter accumulation.The photosynthetic rate and transpiration rate could recover somewhat by rewatering as compensation.2) Waterlogging also affected the physiological functions of tobacco leaf greatly,which aggravated the membrane lipid peroxidation and was more harmful than drought stress.3) Both drought and waterlogging increased the reflectivity of visible light from tobacco plants in the region of 460-670 nm while decreased that of near infrared in the region of 780-1050 nm.Therefore,spectral characters can be used as an important means for diagnosing the extent of water stress on flue-cured tobacco.