| 摘要: |
| 秀丽兜兰（Paphiopedilum venustum）为国家一级保护野生植物，兼具观赏价值和重要保护意义。为明确蒴果成熟的关键时期及适宜采收时间，本研究以以授粉后天数（DAP）0～360的秀丽兜兰蒴果及种子为材料，通过蒴果表型观测、种子形态观测、有胚率检测及活力测定等方法，研究其蒴果和种子的生长发育动态。结果表明：（1）秀丽兜兰蒴果表面被蜡质，随发育时期增加蒴果颜色由深紫转为青绿色，成熟的蒴果表皮坚硬。30～60 DAP和240～270 DAP为蒴果的快速发育期；（2）0～210 DAP秀丽兜兰种子未分化，210～300 DAP种子白色，黏着在胎座组织上，300～360 DAP种子淡黄色至黄褐色，逐渐干燥脱离胎座，360 DAP的种子长宽及体积均显著高于其他发育时期；0～240 DAP未发现典型种胚结构，240 DAP时种胚开始发育，360 DAP的种子有胚率最高为90.55% ± 1.62；330 DAP时TTC法测定的种子活力最显著，为68.33% ± 3.06，330 DAP后随着授粉后时间增加，种皮质密，染色率下降。（3）从蒴果及种子整体发育来看，秀丽兜兰的蒴果发育过程中存在两个快速发育期，30～60 DAP和240～270 DAP，在这两个快速发育期蒴果的长度、宽度都显著提升，种子发育，鲜重积累，秀丽兜兰的种子和种胚快速发育期为240～270 DAP，这与第二次蒴果快速发育期吻合。综上，在人工栽培下，秀丽兜兰的最佳采收期为330 DAP。蒴果及种子的动态发育分析为秀丽兜兰的种质保存和人工繁殖提供了理论基础和技术支持。 |
| 关键词: 秀丽兜兰 果龄 蒴果发育 种子发育；种子质量 |
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| Fund project:西藏农牧大学研究生创新项目(YJS2024-32)；西藏自治区重点研发计划专项XZ202502ZY0044；西藏自治区科技计划项目（XZ202401ZY0036）；西藏农牧大学林学博士点(一期)533325001。高原特色农牧科技小院建设及综合服务能力提升(XK2024-01,XK2024-04,YJSJD2025-6)。 |
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| Dynamics of Capsule and Seed Development in the Rare and Endangered Orchid Paphiopedilum venustum |
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Collge of Forestry and Grassland,Xizang Agriculture and Animal Husbandry University/The Orchid Conservation Center of Xizang,Xizang Plateau Forest Ecology Key Laboratory of the Ministry of Education,Linzhi,Xizang
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| Abstract: |
| Paphiopedilum venustum is a wild plant under National Class I protection, with ornamental value and conservation importance. To determine the critical period for capsule maturation and the optimal harvest time, this study investigated the growth and development dynamics of the capsules and seeds of P. venustum . Capsules and seeds at 0～360 days after pollination (DAP) were used as materials, and analyses were conducted through phenotypic observation of capsules, morphological observation of seeds, and assessments of embryo rate and seed viability. Results: (1) The capsule surface of P. venustum is waxy . As the developmental stage progresses, the capsule color changes from deep purple to greenish, and the mature capsule epidermis becomes hard. Two rapid growth phases were observed at 30～60 DAP and 240～270 DAP. (2) From 0～210 DAP, P. venustum seeds were undifferentiated. During 210～300 DAP, seeds white in color, and adhered to the placental tissue. From 300～360 DAP, seeds turned from light yellow to yellowish-brown, gradually dried, and detached from the placenta. Seed length, width, and volume at 360 DAP were significantly higher than those at other developmental stages. No typical embryo structure was found from 0～240 DAP; embryo development began at 240 DAP. The highest embryo rate, 90.55% ± 1.62, was observed at 360 DAP. Seed viability, determined by the TTC method, was most significant at 330 DAP, reaching 68.33% ± 3.06. After 330 DAP, with increasing time post-pollination, the seed coat became denser, and the staining rate decreased. (3) Considering the overall development of capsules and seeds, two rapid growth phases exist during capsule development (30～60 DAP and 240～270 DAP), during which capsule length and width increase significantly. The rapid development phase for seeds and embryos (240～270 DAP) coincides with the second rapid capsule growth phase. In conclusion, under artificial cultivation conditions, the optimal harvest time for P. venustum is 330 DAP. The dynamic analysis of capsule and seed development provides a theoretical foundation and technical support for germplasm conservation and artificial propagation of P. venustum. |
| Key words: Paphiopedilum venustum Capsule age Capsule development Seed development Seed quality. |
