干旱胁迫下氮对烤烟生长及生理特性的影响

为了探究干旱胁迫下氮对烤烟生长及生理特性的影响,利用烤烟品种吉烟9号为材料,设置5个氮用量处理进行盆栽试验。试验结果表明,在农艺性状上,干旱胁迫下处理E(0.6g/kg土壤)的各项指标都优于其他处理,正常供水条件下,处理D(0.45 g/kg土壤)表现最佳,当氮用量增至0.6g/kg土壤时会抑制烟株的生长。在生理特性上,随着干旱胁迫的逐渐加剧烟叶的净光合速率、气孔导度、蒸腾速率、叶绿素含量逐渐降低,而脯氨酸含量则逐渐升高,正常供水条件下个体指标均保持平稳,说明烤烟光合作用及抗逆指标对干旱胁迫非常敏感。各施氮水平间比较表明,较高的氮素营养有利于烤烟通过生理过程的调节来抵御干旱的侵袭,减小干旱损失。

Effects of Drought Stress and N Rate on Growth and Physiological Characters of Flue-cured Tobacco

Effect of drought stress and N rate on growth and physiological characters of flue-cured tobacco was studied using pot-cultured 'Jiyan 9' at 5 levels of N application.The results showed that agronomic characters of treatment E(0.6 g/kg) were better than other treatments under drought stress.Plants of treatment D(0.45g/kg) were the best under normal water conditions.Growth of tobacco plants was decreased when the N rate go up to 0.6g/kg.As the drought continued,net photosynthetic rate,stomatal conductance,transpiration rate and chlorophyll content decreased step by step,but proline content increased step by step.The results showed that photosynthesis and stress indexes of flue-cured tobacco were very sensitive to drought stress.Comparing of all N application treatments showed that high nitrogen was propitious for flue-cured tobacco to tolerate drought stress by the modulation of physiological process and to decrease the loss of drought.