不同生育期水分胁迫对烤烟生理特性及化学品质的影响

采用盆栽试验研究了不同生育期水分胁迫对烤烟生理特性及品质的影响.结果表明,烤烟成熟期不同水分处理的中部叶和上部叶蛋白质、烟碱、总氮含量增加;总糖、还原糖含量降低且土壤干旱比水分过多时下降的多,使得烟叶的品质降低;糖碱比、氮碱比、施木克值以轻度干旱(65%处理)较合理.在烤烟不同生育时期,土壤干旱或水分过多,丙二醛含量、SOD活性、脯氨酸含量升高.土壤干旱或水分过多会导致其根系活力和光合速率下降,最适宜的土壤相对含水量在烤烟生长的团棵期、旺长期、现蕾期和成熟期分别为65%、80%、80%和65%.

Effect of Water Stress on Physiological Characteristic and Chemical Quality during Different Growth Stage of Flue-cured Tobacco

A Pot experiment was used to study the effect of water stress on physiology characteristic and chemistry quality during different growth period of flue-cured tobacco. The result indicated that, in the mature period of flue-cured tobacco, under the different water processing condition, protein, alkali, and total nitrogen in the middle leaf and the upper leaf increased. Total sugar, reducing sugar decreased, which was more severe with soil drought than with water excess, causing quality decrease of tobacco leaf. The sugar/nicotine, nitrogen/nicotine, and smoking value of flue-cured tobacco were reasonable with mild drought. During the different growth period of flue-cured tobacco, when the soil was drought or the water was excessive, MDA content, SOD activity, and PRO increased. Soil drought or the water excessive caused decline of the root system vigor and the photosynthesis. The optium soil moisture content for resettling stage, vigorous growing stage, budding stage, and mature stage was 65%, 80%, 80%, 65%, respectively.