Abstract: Using nine kinds of cyclamen（Cyclamen persicum Mill.） seedlings as test materials, the influence of temperature on the physiological and biochemical indexes and growth characteristics of seedlings was systematically analyzed, the high temperature resistance of different varieties of cyclamen plants were studied, and an attempt was made to improve the high temperature resistance of seedlings by introducing exogenous antioxidants. The results showed that cyclamen seedlings had a strong ability to tolerate high temperatures in a short period of time. The leaf thickness and number of the seedlings could be used as morphological indicators for the study of heat resistance; at the same time, the leaf cell membrane permeability, superoxide anion and the content of malondialdehyde had a significant correlation with temperature. High temperature stress would increase the membrane lipid peroxidation of cyclamen seedlings and damage the cell membrane and decrease photosynthesis. Among them, the Dutch varieties had the worst heat resistance, and the Japanese and French varieties had stronger heat resistance; the application of antioxidants could alleviate the high temperature damage to the plants, and the 100 mg/L cysteine treatment had the best effect. The research results can provide a more scientific basis for the identification of heat resistance of cyclamen.

Key words: cyclamen（Cyclamen persicum Mill.）, physiological and biochemical index, heat resistance, growth characteristics, antioxidant