论文部分内容阅读
严重干旱胁迫条件下烟株的生长明显受阻，产量下降。增施钾肥可提高烟叶中钾的含量，增加干物质积累，并能使叶片中的各种化学物质充分转化、含量协调，从而提高了干旱条件下烤烟的产量，并能改善品质。钾素的生理调节机理是增强烤烟叶片的保水力，降低失水速率和蒸腾速率。细胞膜在干旱条件下保持其完整性，表现为叶片的相对电导率和伤害率下降。另外，干旱胁迫下钾素能够增强烟株对超氧化物歧化酶（ＳＯＤ）活性的调节，有利于消除活性氧自由基，减轻了干旱胁迫对细胞膜的伤害，从而增强烤烟的抗旱能力，并使恢复供水后的烟株迅速恢复生长。
Under severe drought stress, the growth of tobacco plants was obviously blocked and the yield dropped. Increasing potassium fertilizer can increase the content of potassium in tobacco leaf, increase the accumulation of dry matter, and make all kinds of chemical substances in leaves fully transformed and coordinated, thus improving the yield of flue-cured tobacco under drought conditions and improving the quality. Physiological regulation mechanism of potassium is to enhance water retention of tobacco leaves, reduce water loss rate and transpiration rate. The cell membrane maintains its integrity under drought conditions, showing a decrease in the relative conductivity and injury rate of the leaves. In addition, under the drought stress, potassium could enhance the regulation of superoxide dismutase (SOD) activity in tobacco plants, eliminate the active oxygen free radicals, alleviate the damage of cell membrane by drought stress, and enhance the drought resistance of flue-cured tobacco After the restoration of water supply tobacco plants quickly restored growth.