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林业科学 ›› 2025, Vol. 61 ›› Issue (4): 129-139.doi: 10.11707/j.1001-7488.LYKX20240144

• 研究论文 • 上一篇    

麻栎种子和胚方脱水敏感性及其低温贮藏技术

张铭佳1, 仝伯强2, 曲凯1, 咸洋2, 崔程程1, 王永正3, 臧一村3, 韩彪2   

  1. 1. 北京林业大学生物科学与技术学院 北京 100083;
    2. 暖温带林草种质资源保存与利用国家林业和草原局重点实验室 山东省林草种质资源中心 济南 250000;
    3. 山东农业大学林学院 泰安 271000
  • 收稿日期:2024-03-15 修回日期:2024-05-29 发布日期:2025-04-21
  • 通讯作者: 韩彪为通信作者。E-mail:hanbiaook831228@163.com。
  • 基金资助:
    林草科技创新发展与研究项目——第四批林草科技青拔人才项目(2024132009);山东省博士后创新项目(SDCX-ZG-202203059)。

Desiccation Sensitivity and Low-Temperature Preservation Techniques of Quercus acutissim Seeds and Embryonic Axes

Zhang Mingjia1, Tong Boqiang2, Qu Kai1, Xian Yang2, Cui Chengcheng1, Wang Yongzheng3, Zang Yicun3, Han Biao2   

  1. 1. College of Biological Science and Technology, Beijing Forestry University Beijing 100083;
    2. Key Laboratory of National Forestry and Grassland Administration on Conservation and Utilization of Warm Temperate Zone Forest and Grass Germplasm Resources Shandong Provincial Center of Forest and Grass Germplasm Resources Jinan 250102;
    3. College of Forestry, Shandong Agricultural University Tai’an 271000
  • Received:2024-03-15 Revised:2024-05-29 Published:2025-04-21

摘要: 目的 研究麻栎种子和胚方的脱水敏感性特征与临界含水量,探索麻栎种子低温保存技术和胚方超低温保存技术,为麻栎等顽拗性种子的保存提供技术参考。方法 以野生麻栎种子为试验材料,采用硅胶减重法快速脱水至目标含水量,测定不同含水量种子和胚方的萌发指标;利用差示扫描量热技术(DSC)测定不同含水量胚轴和子叶的热力学参数,根据含水量和对应热焓的关系测算胚方结晶临界含水量;应用低温密封保存法保存不同含水量的种子,运用玻璃化法在超低温环境中保存不同含水量的胚方。结果 1) 麻栎不同含水量种子和胚方萌发特征显示,二者分别从初始含水量34.90%和44.14% 降至10.00%,萌发率从93.00%和90.00%降至5.00%和60.00%。2) 不同含水量麻栎胚轴和子叶DSC结果显示,随着胚轴和子叶含水量降低,结晶起始温度、峰值温度和热焓均呈规律性下降趋势,与含水量显著正相关;不同含水量胚轴平均热焓高于子叶平均热焓,胚轴自由水含量高于子叶自由水含量,初步判定本批次麻栎胚方理论结晶临界含水量为11.72%。3) 脱水对麻栎种子生理生化特性的影响结果显示,随着脱水程度加深,种子细胞超氧化物歧化酶(SOD)和过氧化物酶(POD)活性、脯氨酸(PRO)和 丙二醛(MDA)含量均呈先上升后下降趋势。4) 麻栎种子低温保存结果显示,初始含水量种子在4 ℃下保存21天,萌发活力没有变化,重度脱水(10.00%~20.00%)种子能够忍受一定程度的低温伤害;不同含水量胚方超低温保存结果显示,含水量对超低温保存结果有显著影响,PVS2预处理30 min时10.00%和15.00%含水量麻栎胚方成活率分别为5.00%和3.00%,不同含水量胚方经预处理和超低温保存后,热力学特征发生改变,15.00%含水量麻栎胚方重新获得自由水。结论 麻栎种子和胚方萌发率随含水量下降而降低,具有脱水敏感性特征,脱水对麻栎种子生理生化特性有显著影响;麻栎胚方理论结晶临界含水量为11.72%;超低温保存麻栎胚方具有可行性,但仍需完善保存方法,提高胚方超低温保存后恢复萌发率。

关键词: 麻栎, 顽拗性种子, 脱水敏感性, 超低温保存, 差示扫描量热技术

Abstract: Objective This study aims to investigate the desiccation sensitivity as well as the critical moisture content of the seed and embryonic axis of Quercus acutissim and explore low-temperature preservation techniques for Q. acutissima seeds and ultra-low temperature preservation techniques for the embryonic axis, in order to provide technical guidance for the preservation of recalcitrant seeds such as Q. acutissima. Method Wild Q. acutissim seeds were used as experimental materials, the silica gel weight reduction method was used to rapidly dehydrate the seeds to the target moisture content, and then the germination indexes of seeds and embryonic axes with different moisture contents were determined. The differential scanning calorimetry (DSC) was employed to determine the thermodynamic parameters of embryonic axes and cotyledons with different moisture contents, and the critical moisture content of crystallization in the embryonic axis was evaluated according to the relationship between moisture content and corresponding enthalpy. The low-temperature sealed storage method was used to preserve seeds with different moisture contents, and the vitrification method was used for cryopreservation of the embryonic axis. Result 1) When the initial moisture content of the seeds and embryonic axes decreased from 34.90% and 44.14% to 10.00%, their germination percentage decreased from 93.00% and 90.00% to 5.00% and 52.00%, respectively. 2) The DSC results of Q. acutissim embryonic axis and cotyledon with different moisture contents showed that with the decrease of moisture content of embryonic axis and cotyledon, the crystallization initiation temperature, peak temperature and enthalpy value showed a regular downward trend, which were significantly positively correlated with moisture content. The average enthalpy value of the embryonic axis was higher than that of the cotyledon, and the free moisture content of the embryonic axis was higher than that of the cotyledon. It was preliminarily determined that the theoretical critical moisture content of crystallization in this batch of the embryonic axes was 11.72%. 3) The effects of dehydration on the physiological and biochemical characteristics of Q. acutissima seeds showed that as dehydration progressed, the activities of superoxide dismutase (SOD) and peroxidase (POD), as well as the contents of proline (PRO) and malondialdehyde (MDA) in seeds initially increased and then decreased. 4) Q. acutissim seeds with initial moisture content stored at 4 ℃ for 21 days showed no change in the germination vitality, and the seeds with severe dehydration (10%–20%) were still able to tolerate a certain degree of low temperature damage. The results of cryopreservation of embryonic axis with different moisture contents showed that moisture content had a significant impact on the results of cryopreservation. When pretreated with PVS2 for 30 min before cryopreservation, the embryonic axis with 10.00% and 15.00% moisture content had a 5.00% and 3.00% survival rate, respectively, and the thermodynamic characteristics of the embryonic axis with different moisture content changed. The embryonic axis with 15.00% moisture content regained free moisture. Conclusion The germination rate of Q. acutissim seeds and embryonic axes decreases with the decrease of moisture content, which is a typical characteristics of recalcitrant seeds with the dehydration sensitivity. Dehydration has a significant effect on the physiological and biochemical characteristics of the seeds. The theoretical critical moisture content of crystallization in Q. acutissim embryonic axis is 11.72%. Cryopreservation of Q. acutissimembryonic axis is possible, but the method still needs adjustment to increase the recovery of germination rate, and then is applied to the long-term preservation of the recalcitrant seed.

Key words: Quercus acutissim, desiccation sensitivity, cryopreservation, recalcitrant seeds, differential scanning calorimetry (DSC).

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