Abstract: In order to study the effect of foliar spraying of exogenous selenium on the growth and quality of dandelion, a pot experiment was used to spray dandelion leaves with different concentrations of sodium selenite solution （0, 100, 200, 300, 400 μmol/L）, the effects of selenium on dandelion growth, photosynthetic system, antioxidant enzyme system, active ingredients and selenium content were analyzed. The results showed that, with the increase of spraying selenium concentration, growth indexes such as root length and fresh weight of dandelion showed a trend of first increasing and then decreasing. Compared with the control, the application of 200 μmol/L sodium selenite could significantly improve the photosynthesis rate and photochemical reaction efficiency of dandelion, and increase the content of photosynthetic pigments. The activities of SOD and CAT in dandelion leaves were the highest when the selenium concentration was 200 μmol/L, and the activity of POD was the highest when the concentration of selenium was 300 μmol/L （P<0.05）. Selenium application could effectively increase the content of chlorogenic acids, total flavonoids and total polyphenols in dandelion. Compared with the control, when the selenium concentration was 200 μmol/L, the contents of total flavonoids and total polyphenols were significantly increased by 49.73% and 31.34%, respectively. The selenium content of dandelion increased significantly after selenium application, and the selenium content of leaves and roots and the amount of selenium application were in line with a quadratic equation. Dandelion leaves were sensitive to changes in exogenous selenium concentration and were the main part of selenium enrichment. The study concluded that foliar application of 200 μmol/L sodium selenite was the best concentration for culturing selenium-enriched dandelion.

Key words: selenium, dandelion（Taraxacum mongolicum Hand.-Mazz.）, growing, physiological characteristics