摘要： 采用低温下发芽鉴定，田间分期播种和人工低温处理完整植株等方法，研究了8个玉米自交系苗期耐冷性反应。结果表明：玉米自交系的耐冷性可以分为强、中、弱等类型。玉米自交系的主要耐冷特征有耐冷性总指数、发芽临界温度、早播幼苗地上部分干重、早播叶片束缚水含量、叶片膜透性相对电导值达50%的时间、叶片超弱发光强度达1/2Max的时间和植株干枯率达50%的时间等指标。常温下游离脯氨酸含量与耐冷性呈正相关，低温下脯氨酸积累量与耐冷性呈负相关。

关键词: 玉米自交系, 耐冷性, 超弱发光, 游离脯氨酸

Abstract: The cold tolerance of eight maize inbreds was studied under natural and controlled low temperature conditions.According to their response to cold the eight inbreds were respectively classified into strong,intermediate and weak cold tolerant types.The principal cold tolerance characters include the total index of juvenile cold tolerance,the minimum critical temperature for seed germination,seedling dry weight,bound water content,the time for relative electrical conductivity to reach 50%,the time for ultraweak fluorescence to reach jiMax.,the time for percentage of withered plants to reach 50%,etc.At normal temperature the pro-line content in maize inbred leaves was positively correlated to cold tolerance,the free proline accumulation at low temperature was negatively correlated to cold tolerance.

Key words: Maize inbred, Cold tolerance, Ultraweak fluorescence, Free proline