Effect of Potassium Nutrition on Anthracnose Occurrence and Defense Enzyme Activity in Flowering Chinese Cabbage
GUO Ju-xian1，2，LIU Yu-tao1，YANG Xian1*
1College of Horticulture，South China Agricultural University，Guangzhou 510642，Guangdong，China|2 Vegetable Research Institute，Guangdong Academy of Agricultural Sciences，Guangzhou 510640，Guangdong，China
Abstract：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．
