Abstract:

In order to study the effects of potassium fertilizer on the activities of defensive enzymes and triterpene accumulation in the leaves of birch which paved the way for establishing a cultivating system of birch to produce triterpene via potassium application. 3 doses of potassium fertilizer (KCl), 15 g, 10 g and 5 g were applied to 2-year seedlings. Then the content of triterpene and the activity of defensive enzymes were determined by a spectrophotometer. The results showed that potassium fertilizer raised the activity of SOD, CAT and POD to different extent, respectively. The content of soluble sugar within the leaves also rose. Among the three doses, the mediate one (5 g) brought the best effect to triterpene accumulation [up to 42.16 mg/(g?DW)]. Mediate potassium could effectively promote the accumulation of triterpene within the leaves of birch when were fertilized during the seasons for fast growing (from July to September in Harbin).