钾营养对菜薹（菜心）炭疽病发生和植株防御酶活性的影响

通过接种炭疽病菌，测定了不同钾营养水平下菜薹的抗病品种和感病品种的病情指数、苯丙氨酸解氨酶（PAL）、多酚氧化酶（PPO）和过氧化物酶（POD）活性。结果表明，不同钾营养水平处理的菜薹炭疽病发病程度均比对照轻，病情指数明显下降，钾营养处理明显增加了菜薹对炭疽病的抗性水平。随着钾营养处理水平的提高，抗病品种的PAL活性、PPO活性都呈上升趋势，而钾营养处理的POD活性则低于对照|感病品种的PAL活性、PPO活性、POD活性都呈先上升后下降趋势，酶活性在中K处理时达到最高。

Effect of Potassium Nutrition on Anthracnose Occurrence and Defense Enzyme Activity in Flowering Chinese Cabbage

The disease index of disease resistant and susceptible breeds in flowering Chinese cabbage(Brassica parachinensis)treated by different levels of potassium nutrition and PAL,PPO,POD activities were tested,respectively by inoculating Colletotrichum higginsianum.The results showed that the morbidity degree of Colletotrichum higginsianum of all breeds treated by different levels of potassium nutrition are lower than that of the control,and the disease indexes were decreasing remarkably,indicating that the disease resistance was strengthened by potassium nutrition treatment.Along with the increase of potassium nutrition treatment level,the PAL,PPO activities of those resistant breeds were increasing,while the POD activities were lower than that of the control.The PAL,PPO,POD activities of those susceptible breeds showed a trend of increasing first,then decreasing.And the enzyme activities reached the highest level in medium potassium nutrition treatment.