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| 濒危植物海南龙血树种子休眠机理及其生态学意义 |
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郑道君1,2,3, 杨立荣1,3, 云 勇1,3, 陈加利1,3, 陈 宣1,3, 姜殿强1,3, 张治礼1,3*
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1. 海南省农业科学院 热带园艺研究所, 海口 571100;2. 海南省农业科学院 农业环境与土壤研究所,
海口 571100;3. 海南省热带特种经济植物种质资源创新利用重点实验室, 海口 571100
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| 摘要: |
| 为明确濒危植物海南龙血树(Dracaena cambodiana)种子的休眠机理,该文对海南龙血树休眠类型及破解方法进行了系统研究,并结合海南龙血树的生境条件,对海南龙血树种子休眠的生态学意义进行了探讨。结果表明:海南龙血树种皮吸水性良好,40 h内达到萌发所需含水量; 种胚发育完全,离体胚2 d开始萌发,萌发率达100%; 去珠孔端组织种子的萌发情况与离体胚的一致,质密珠孔端组织的机械束缚是种子萌发障碍的直接原因; 种子含有萌发抑制物质,其清水粗提物对白菜种子萌发率和幼苗根生长存在显著抑制作用; 低温贮藏和快速脱水均能有效解除海南龙血树种子休眠,提高种子的萌发率和整齐度,萌发率可达到100%。分析认为抑制物质的存在致使种胚生长势弱而无法打破质密珠孔端组织的机械束缚,导致海南龙血树种子休眠,属生理休眠; 海南龙血树种子休眠特性使其种子萌发或幼苗生长适应生境条件的季节变化,保证种群得以延续与更新。 |
| 关键词: 海南龙血树, 种子休眠机理, 休眠类型, 休眠破解, 生态适应性 |
| DOI：10.11931/guihaia.gxzw201701024 |
| 分类号:Q945 |
| 文章编号:1000-3142(2017)12-1551-09 |
| Fund project:国家自然科学基金(31360071); 海南省重点研发计划项目(ZDYF2016179)[Supported by the National Natural Science Foundation of China(31360071); the National Key Research and Development Program of Hainan Province(ZDYF2016179)]。 |
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| Seed dormancy mechanism and its ecological significance of endangered species Dracaena cambodiana |
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ZHENG Dao-Jun1,2,3, YANG Li-Rong1,3, YUN Yong1,3, CHEN Jia-Li1,3,
CHEN Xuan1,3, JIANG Dian-Qiang1,3, ZHANG Zhi-Li1,3*
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1. Institute of Tropical Herticultuer Research, Hainan Academy of Agricultural Sciences, Haikou 571100, China;2. Agricultural
Environment and Soil Research Institute, Hainan Academy of Agricultural Sciences, Haikou 571100, China;3. Key
Laboratory of Tropic Special Economic Plant Innovation and Utilization, Haikou 571100, China
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| Abstract: |
| In order to understand the dormancy mechanism of Dracaena cambodiana seed, the dormancy types and methods for seed dormancy breaking were studied systematically, and the ecological significance for dormancy mechanism of D. cambodiana seeds were also investigated. The results showed that the hydroscopicity of D. cambodiana spermoderm was good with(42.60 ± 0.08)% seed imbibition rates after 40 h; excised embryos began to geminate after 2 d with a germination rate of 100%, suggesting a mature embryo for D. cambodiana; and the germination of seeds without micropylar structure was the same to excised embryos, which showed the main reasons for failure of germination was the mechanical resistances of the hard micropylar structure; there were inhibitory substances in the seeds since when cabbage seeds were treated with the water crude extracts of D. cambodiana seeds for about 48 h, the seed germination and seedling growth of cabbage was inhibited obviously. Both rapid dehydration and storage under low temperature can break effectively the dormancy of D. cambodiana seeds, to increase the germination rate to 100% and germination uniformity. The analysis suggest that the growth potentials of the embryo maybe limited by seed-inhibitory substance are not able to break the mechanical resistances of the hard micropylar structure, and this is the dormancy mechanism of D. cambodiana seeds, which belong to physiological dormancy; the seed germination and seedling growth of D. cambodiana with the seed dormancy can adapt to the seasonal change of habitat conditions, which ensure the exist and regeneration of D. cambodiana population. |
| Key words: Dracaena cambodiana, seed dormancy mechanism, types of seed dormancy, seed dormancy breaking, ecological adaptability |
