Primary physiological dormancy and secondary physiological dormancy of Korean pine seeds restrict the regeneration of broad-leaved Korean pine (Pinus koraiensis) mixed forest. Dry and imbibed seeds were stratified at 1 °C and 5 °C for 1, 2, 4 and 6 months. Germination percentage, mean germination time (MGT) and germination rate index (GRI) were measured to determine the optimal low temperature and its duration for the release of primary physiological dormancy. Once primary physiological dormancy was released through cold stratification, seeds were stored in an environment in which the temperature progressively increased from 5 to 25 °C. After one month of storage at each storage temperature, the germination percentage, MGT and GRI were measured to determine the threshold temperature for the induction of secondary physiological dormancy. Both dry and imbibed seeds not only exhibited a high germination percentage (approximately 80%) but also germinated rapidly (MGT and GRI were 17 days and 2.36, respectively) after 6 months of storage at either 1 °C or 5 °C. The germination percentage of cold stratified seeds gradually decreased from 78% (5 °C) to 72% (10 °C), 55% (15 °C), 10% (20 °C) and 8% (25 °C). The results of this study suggest that stratifying seeds at 1 °C or 5 °C for 6 months releases primary physiological dormancy. The induction of secondary physiological dormancy occurs at temperatures above 15 °C.

中文翻译：

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红松（Pinus koraiensis Sieb。et Zucc。）种子释放初级和次级继发生理休眠的温度和长度

红松种子的原始生理休眠和次生生理休眠限制了阔叶红松（红松）的再生）混合森林。将干燥和吸收的种子在1°C和5°C下分层1、2、4和6个月。测量发芽百分比，平均发芽时间（MGT）和发芽率指数（GRI），以确定释放主要生理休眠的最佳低温及其持续时间。通过冷分层释放主要的生理休眠后，将种子储存在温度从5℃逐渐升高到25℃的环境中。在每个储存温度下储存一个月后，测量发芽率，MGT和GRI，以确定诱导次生生理休眠的阈值温度。干种子和吸收种子不仅发芽率高（约80％），而且发芽迅速（MGT和GRI为17天和2.36，分别在1°C或5°C下存放6个月后。冷分层种子的发芽率逐渐从78％（5°C）降至72％（10°C），55％（15°C），10％（20°C）和8％（25°C）。这项研究的结果表明，将种子在1°C或5°C下分层6个月可以释放主要的生理休眠。次级生理休眠的诱导发生在高于15°C的温度下。