Abstract:

The effects of different potassium application levels (0, 75, 150 and 225 kg/hm²) on the physiological characteristics of salvia miltiorrhiza were studied to provide theoretical basis for reasonable application of potassium fertilizer. The results showed that potassium application could reduce the MDA content of Salvia miltiorrhiza. The MDA content was the lowest when potassium was applied at 150 kg/hm². Potassium application was beneficial to increase the activities of SOD, POD and CAT of Salvia miltiorrhiza. At the potassium application level of 150 kg/hm², the activities of SOD and POD of Salvia miltiorrhiza were significantly higher than that of other treatments, and the activities of CAT were also at a higher level, which indicated that proper application of potassium could improve the activity of protective enzymes, inhibit membrane peroxidation, and reduce the production of MDA. The chlorophyll content of Salvia miltiorrhiza increased first and then decreased with the increase of potassium level. When the potassium level was 150 kg/hm², the chlorophyll content of Salvia miltiorrhiza was the highest, the speed of leaf aging was slow.

Key words: Salvia miltiorrhiza, potassium supply level, malondialdehyde, protective enzyme, chlorophyll