天女木兰种子后熟期间的生理生化变化

为了解天女木兰种子后熟期间生理生化变化，探讨解除种子休眠机理及寻找种子快速催芽技术提供参考和依据，将天女木兰种子分别用250 mg/L赤霉素（GA3）溶液和清水浸种48 h，然后进行室外自然低温层积、室内低温层积(5℃)和室内人工控制变温层积(5℃、20 d和10～15℃、10 d交替变换)催芽处理。在层积过程中定期取样测定天女木兰种子的胚长占种子长的比例、呼吸速率、过氧化氢酶活性、过氧化物酶活性、可溶性糖含量等指标。结果表明:采用GA3浸种变温（10～15℃和5℃）层积处理有利于种胚的生长发育；GA3浸种变温处理能提高种子内过氧化氢酶、过氧化物酶的活性，促进种子中可溶性糖含量升高，并能促使形态后熟提前完成。 

Physiological and biochemical changes respond to seed after-ripening in Magnolia sieboldii K.Koch

To understand the physiological and biochemical changes in after-ripening for seeds of Magnolia sieboldii K. Koch, discuss the potential mechanism of breaking seed dormancy and provide the basis and reference for rapid germination, the seeds of M. Sieboldii were pregerminated for 48 hours in 250 mg/L of GA_3 solution and water, respectively. After that, lower temperature stratifications were conducted sequentially for an outdoor environment and indoor environment (5℃), followed by an exposure to alternate temperature from 5℃ for 20 days to 10-15℃for 10 days. The length ratio of embryo to seed, respiration rate, catalase activity, poroxidase activity, soluble sugar of samples from different pregermination treatments were measured. The results showed that alternate temperature (5℃ to 10-15℃) stratification with GA_3solution favored the growth and development of embryos. It increased catalase activity, peroxidase activity, soluble sugar content of seeds, and stimulated morphological maturation of seeds.