Abstract: To explore the effects of silicon and selenium on cold resistance of Dendrobium candidum in low temperature stress, this study is based on Dendrobium candidum seedlings as experimental material, the stress of low temperature 2 ℃ after 7 d, with different concentrations of exogenous silicon and selenium compound spraying on the leaf. The silicon and selenium were all set up 12 kinds of complex dispensing. The results showed that silicon and selenium should be used together in low temperature stress, which was reflected in the increase of chlorophyll content and Pro content, the increase of POD, SOD and CAT activity, and the decrease of MDA content. This indicated that silicon and selenium treatment（50 mg/L silicon+5 mg/L selenium, 50 mg/L silicon+7.5 mg/L selenium） could increase the cold resistance of Dendrobium candidum seedlings, which was achieved by means of enhancing the anti-oxidative enzyme activities, chlorophyll content and Pro content, and decreasing the MDA content to reduce injury of low temperature stress.

Key words: Dendrobium candidum, low temperature stress, compound of silicon and selenium, cold resistance