不同贮藏条件下龙葵种子的季节性休眠特性

龙葵是农田恶性杂草?为明确龙葵种子休眠与季节温度的关系, 研究了室内和室外不同贮藏条件下其种子萌发对温度的响应规律?结果表明, 室外贮藏条件下的龙葵种子萌发呈季节性变化, 从10月到翌年5月, 龙葵种子萌发率均在95%以上, 随着夏季温度的升高, 萌发率从6月开始下降, 9月达到最低值(25.4%), 由此进行年际间休眠和非休眠周期的循环?夏季6月-9月的高温可诱导龙葵种子进入休眠状态, 而秋冬季的相对低温有利于解除种子休眠, 使种子恢复萌发状态?龙葵种子休眠和非休眠状态之间的切换受季节性温度变化的影响?室内贮藏的种子, 由于环境温度较为稳定, 其萌发率年际变化较小, 在20%~50%之间?本文明确了龙葵种子休眠的周期性变化规律, 有助于精准预测其出苗时间, 研究结果可为阐明龙葵种子休眠萌发机制和制订基于萌发调控的绿色防控策略提供依据?

Seasonal dormancy of black nightshade (Solanum nigrum L.) seeds under different storage conditions

Solanum nigrum L.is a worst weed in crop fields. In order to clarify the relationship between dormancy of S. nigrum seeds and seasonal temperature, the response of seed germination to temperature was studied under different indoor and outdoor storage conditions. The results showed that the seed germination of S. nigrum varied seasonally. The germination rate of S. nigrum seeds under outdoor storage was above 95% from October to May, but the germination rate decreased from June as the soil temperature increased in summer and reached its lowest value (25.4%) in September, and then continued the annual dormancy-nondormancy cycle. The high summer temperatures from June to September can induce seed dormancy of S. nigrum, while the relatively low temperatures in autumn and winter help to break seed dormancy and allow them return to the germination state. The transition between dormant and non-dormant states of S. nigrum seeds is influenced by seasonal changes of temperature. S. nigrum seeds stored indoors showed a narrow range of germination rate between 20% and 50% due to the relatively stable ambient temperature. The elucidation of the seed dormancy cycling of S. nigrum is helpful for precise prediction of its seedling emergence. Our results provide an important guidance for revealing the mechanism of S. nigrum seed dormancy and formulating green weed management strategies based on regulation of seed germination.