钾对大白菜软腐病发生及保护酶活性的影响

Effects of Potassium on Soft Rot Incidence and Defense Enzyme Activity in Chinese Cabbage

[目的]探究钾肥在抗大白菜软腐病中的作用。[方法]以德高秋丰王和北京新三号为试验材料,通过大田试验,研究3个施钾水平下(0、200、400 kg/hm^2K_2O)德高秋丰王和北京新三号大白菜产量、软腐病发病率及保护酶活性的变化。[结果]施钾量为200 kg/hm^2时显著提高德高秋丰王的产量,而北京新三号产量在施钾量达到400 kg/hm2时显著提高;随施钾量的提高,两品种大白菜软腐病病情指数都呈现降低的趋势,施钾量在400 kg/hm^2时,病情指数最低;两品种的PPO和POD的活性都随施钾量的提高而增强。[结论]施钾对大白菜产量的效应因品种不同而异,增施钾肥可以通过提高保护酶的活性降低大白菜软腐病病情指数。

[Objective] To study effects of potassium on the resistance to soft rot of Chinese Cabbage.[ Method ] Degaoqiufengwang and Bei-jingxinsanhao were used as the test materials,effects of three different potassium （0 kg/hm2 ,200 kg/hm2 and 400 kg/hm2 ） on the yield,soft rot incidence and change of protective enzyme activity in Chinese cabbage were studied using field experiment.[ Result] Yield of Degaoqiufengwang increased significantly when the amount of potassium applied was 200 kg/hm2 ,but the yield of Beijingxinsanhao increased significantly when the amount of potassium applied was 400 kg/hm2 .With the increase of potassium application,the disease index of soft rot in both two varieties of Chi-nese cabbage showed a downward trend,and the disease index was the lowest when amount of potassium applied at 400 kg/hm2 .The activities of PPO and POD in both varieties increased with the increase of potassium application amount.[ Conclusion] The effect of potassium on the yield of China cabbage varies by variety,application of potassium could reduce the disease index of soft rot in China cabbage through improving the activi-ty of protective enzymes.