不同温度下四川马尔康岷江柏种子的发芽特征

SEED GERMINATION CHARACTERISTICS OF CUPRESSUS CHENGIANA AT DIFFERENT TEMPERATURES IN MAERKANG, SICHUAN

通过对不同温度下岷江柏(Cupressus chengiana S.Y.Hu)种子的发芽特征研究,分析了种子的发芽周期和最适发芽温度,以及温度对种子发芽的影响,并讨论了岷江柏的发芽特征与环境温度的关系.结果表明,种子发芽周期为20 d,其中0～5 d为准备期,5～15 d为对数期.种子发芽温度为5～30℃,适宜发芽温度为10～25℃,5℃和30℃均不利于种子发芽.在贮藏过程中,贮藏开始阶段10℃不利于种子发芽,10～25℃贮藏4～10 mo后的发芽率没有差异.种子最适发芽温度在2003年1月、4月、7月和10月分别为25℃、10℃、15℃和25℃.在不同温度下,种子发芽率没有差异,而种子发芽势和达到50%发芽的天数有显著差异.岷江柏种子的发芽周期和最适发芽温度,以及贮藏过程中的发芽特征与环境温度有着密切的关系,这是它对自然环境的一种适应表现.

Cupressus chengiana S. Y. Hu is a rare and endangered tree in Sichuan and Gansu provinces of China. Its seed germination characteristics at different temperatures were studied. The germination cycle, optimum temperature and effect of temperature on germination were tested. Furthermore, the relationship between germination characteristics and environment temperature was discussed to provide theoretical evidences for reproduction and conservation of C. chengiana . The results showed that the germination cycle was 20 days, including preparing period of 0～5 days and logarithmic phase of 5～15 days. Seed germination temperature ranged from 5 ℃ to 30 ℃, while the optimum temperature was between 10 ℃ and 25 ℃. During seed storage, 10 ℃ was not a favorable temperature for its germination at the beginning stage and the germination rate had no differences after 4～10 months storage at 10～25 ℃. The optimum temperatures for seed germination were 25 ℃, 10 ℃, 15 ℃ and 25 ℃ in January, April, July and October 2003, respectively. At different temperatures, the germination rate of each experimental time had no difference, but the germination potential and the days to 50 % of germination rate of each experiment differed significantly. The germination cycle, optimum temperatures and germination characteristics during storage were closely related with the environment temperature, which is the adaptability of plants to environment. Fig 3, Tab 2, Ref 30