土壤干旱对烤烟生长的影响及机理研究

在盆栽条件下研究了土壤干旱对烤烟ＮＣ８９生长发育的影响及其机理。结果表明，在干旱条件下烟株的生长发育受阻，株高降低，叶片变小，根系发育不良，特别是旺长期干旱对烟株生长的影响更大，且对茎叶生长的影响大于根系，但伸根期轻度土壤干旱可以促进烟株根系的生长。干旱影响烟株生长的机理在于使烟株体内超氧物歧化酶和过氧化氢酶活性下降，清除活性氧自由基的能力减弱，导致植株体内活性氧积累，启动细胞膜脂过氧化作用，造成膜伤害，从而影响烟株的生长发育全过程。

Study on the Effects of Soil Drought Stress on the Growth of Flue-cured Tobacco and its Mechanism

The effects of soil drought stress on the growth and development of flue-cured to-bacco (Nicotiana tabacum L.)and its mechanism were studies with the cultivar NC89 un-der pot experiment.The results showed that the growth and development of flue-cured to-bacco plants were retanded by soil drought stress ,which resulted in the reduce of the stalk height,leaf a rea and the volume of tobacco roots,especially during the vigorous growing stage of tobacco growing phase. Moreover,the influence of drought stress on the growth of the stalks and leaves of tobacco plants were more remarkable than that of the roots. But mild drought stress in root extending stage could promote the growth of tobacco roots. The mechanism of soil drought stress on the growth of tobacco plants was that the activities of superoxide dismutase (SOD)and catalase (CAT) in tobacco plants decreased ,the ability of scavenging activated oxygen free radical was weakened ,which led to the accumulation of activated oxygen in plants. thus ,it induced the membrane-lipid peroxidation,which caused membrane damage. Therefore ,the growth and development of tobacco plants were affect-ed.