College of Horticulture and Landscape Architecture, Yangzhou University, Yangzhou, 225009, China.
BMC Plant Biol. 2023 Jul 5;23(1):350. doi: 10.1186/s12870-023-04357-x.
Seed dormancy and germination are key components of plant regeneration strategies. Aconitum barbatum is a plant commonly found in northeast China. Although it has potential for use in gardening and landscaping, its seed dormancy and regeneration strategy, which adapt to its natural habitat, are not well understood. Our aim was to identify conditions for breaking A. barbatum seed dormancy and determine its dormancy type. Embryo growth and germination were determined by collecting seeds over time in the field. Laboratory experiments that control light, temperature, and stratification period were conducted to assess dormancy breaking and germination, and GA was used to identify dormancy type.
Seeds of A. barbatum have undeveloped embryos with physiological dormancy at maturity in autumn. The embryo-to-seed length ratio increases from 0.33 to 0.78 before the emergence of the radical. Under natural environmental conditions, embryo development begins in early winter. Laboratory experiments have shown that long-term incubation under 4 °C (cold stratification) promotes embryo development and seed dormancy break. With an extension of cold stratification, an increase in germination percentages was observed when seeds were transferred from 4 °C to warmer temperatures. Seeds exposed to light during incubation show a higher germination percentage than those kept in the dark. Seed germination can also be enhanced by a 100 mg/L GA concentration.
Seeds of A. barbatum display intermediate complex morphophysiological dormancy at maturity. In addition to the underdeveloped embryo, there are also physiological barriers that prevent the embryo from germinating. Dormancy breaking of A. barbatum seeds can be achieved by natural winter cold stratification, allowing seeds to germinate and sprout seedlings at the beginning of the following growing season. Our findings provide valuable insights into the seed dormancy and regeneration strategy of A. barbatum, which could facilitate its effective utilization in gardening and landscaping.
种子休眠和萌发是植物再生策略的关键组成部分。乌头是中国东北常见的一种植物。虽然它具有用于园艺和景观美化的潜力，但它的种子休眠和适应其自然栖息地的再生策略尚未得到很好的理解。我们的目的是确定打破乌头种子休眠的条件，并确定其休眠类型。通过随时间在野外收集种子来确定胚胎生长和萌发。进行了控制光照、温度和分层期的实验室实验，以评估休眠破除和萌发，并用 GA 来确定休眠类型。
乌头种子在秋季成熟时具有未发育的胚胎和生理休眠。胚胎与种子长度比从 0.33 增加到 0.78，然后出现主根。在自然环境条件下，胚胎发育始于初冬。实验室实验表明，4°C（低温层积）下的长期孵育促进胚胎发育和种子休眠破除。随着冷层积的延长，当种子从 4°C转移到较温暖的温度时，观察到发芽百分比增加。在孵育过程中暴露于光照下的种子比在黑暗中保持的种子具有更高的发芽百分比。用 100mg/L GA 浓度也可以增强种子的萌发。
乌头种子在成熟时表现出中间复杂的形态生理休眠。除了未发育的胚胎外，还有阻止胚胎萌发的生理障碍。通过自然冬季低温层积可以打破乌头种子的休眠，使种子在次年生长季节开始时发芽和幼苗生长。我们的研究结果为乌头的种子休眠和再生策略提供了有价值的见解，这有助于其在园艺和景观美化中的有效利用。
