氯化钾对干旱胁迫下马铃薯幼苗抗旱性的影响及其机制研究

探究了KCl对干旱胁迫下马铃薯幼苗抗旱性的影响及其机制。研究结果表明：增施KCl（0.70 g·株^-1）显著缓解干旱胁迫下马铃薯幼苗叶片相对含水量和叶绿素含量的降低，抑制叶片MDA含量和相对电导率的升高，相对 提高叶片脯氨酸含量、可溶性糖含量、抗氧化酶（SOD、CAT）活性、净光合速率和水分利用效率；增施KCl还相对提高了马铃薯的株高、基径、单株匍匐茎数量和单株产量，增施氯化钾使干旱胁迫条件下马铃薯植株株高、茎粗、单株匍匐茎数和单株产量分别相对提高6.32%、18.28%、13.75%和29.45%。由此可以认为，在干旱条件下增施氯化钾可通过提高马铃薯幼苗的保水能力，缓解干旱胁迫造成的抗氧化酶活性下降并相对提高渗透调节物质含量，减轻干旱胁迫对光合作用和生长发育的不良影响，从而显著提高马铃薯幼苗的抗旱性。

Effect of potassium chloride on drought resistance of potato seedlings

Effect of potassium chloride (KCl) on drought resistance of potato seedlings were investigated. The results showed that KCl relieved the typical symptom of leaf produced by drought, such as maintaining contents of water, chlorophyll, and MDA and increasing the contents of proline and soluble sugar and the activities of superoxide dismutase (SOD) and catalase(CAT). In addition, it decreased transpiration rate, whereas improved the net photosynthetic rate, water use efficiency and the contents of starch and vitamin C. Plant height, base diameter, stolon number and yield per plant were increased by 6.32%, 18.28%, 13.75%, and 29.45%, respectively, when applying 0.7g KCl/seedling. In su mmary, KCl help to develop effective resistance of potato seedling to drought by improving the water retaining capacity and activating the antioxidative system.