关键词: 玉米, 苗期, 冷袭, 敏感性, 离乳期

Abstract: The studies concerns with elect ronic conductivity, nit rate reductase(NR) activity, solubility protein content, solubility sugar, sucrose content, K⁺, Mg²⁺ and Ca²⁺ content of lixivium of plants, plant height, plant dry weight, plant fresh weight and dry matter weight of remain seeds of corn during germination under chilling(3.0℃) condition. Height, dry and fresh weight of seedlings decreased, solubility protein, solubility sugar and sucrose content assume the trend of decrease along with the increase of leaf age and day-age, but relative electronic conductivity, K⁺, Mg²⁺ and Ca²⁺ content of lixivium of plants submit the trend of increase. These illuminate accordingly that the chilling resistance of corn seedlings is decreased gradually during the autotrophic period transformed from heterot rophic period, i. e. chilling sensitivity is increased gradually. The difference of apiece index between chilling treated and contract plant are biggest at 15 d(or 17 d) without exception, that account for chilling sensitivity of corn seedlings is biggest at this period as independent of albumen period.

Key words: Maize, seedling, chilling, sensitivity, independent of albumen period