Knowledge of seed dormancy and optimal propagation techniques is crucial for successful ex situ restoration and reintroduction projects, and determining the seed storage behaviour of a species is critical for the long-term conservation of seeds, further supporting future ex situ efforts. Eryngium sparganophyllum (Apiaceae) is a globally critically endangered plant species endemic to ciénega wetlands of southwest North America. To support in situ and ex situ conservation efforts of E. sparganophyllum, we asked (i) how does the embryo: seed (E:S) ratio change over time once imbibed, (ii) how does germination respond with varying periods of exposure to cold (5°C) and warm (25°C) stratification, and concentrations of gibberellic acid (GA₃). By answering these questions, (iii) can dormancy class be inferred, and (iv) what storage behaviour category is exhibited? To answer these questions, we collected seeds in Southern Arizona from one of the few remaining wild populations. We measured embryo growth and tested the effects of cold (0–18 weeks) and warm (0 and 4 weeks) stratification, and 0–1000 ppm gibberellic acid on germination. We also tested the effects of cold (−80°C) dry (~20% equilibrium relative humidity) storage on germination. We found that (i) embryos grow inside seeds prior to germination; (ii) compared to control, cold stratification for at least 6 weeks increased germination and warm stratification had no effect; (iii) 1000-ppm GA₃ had the highest germination success; (iv) therefore this species exhibits morphophysiological dormancy; and (v) seeds are orthodox and can therefore be conserved using conventional storage methods. This information will aid managers in the propagation of E. sparganophyllum that is crucial for in situ reintroduction and restoration projects, and seed banking represents a critical ex situ conservation strategy for the preservation of this species.

中文翻译：

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香é特有种，香sp刺菜（ae科）的保护种子生理

种子休眠和最佳繁殖技术的知识对于成功的异地恢复和再引入项目至关重要，而确定物种的种子贮藏行为对种子的长期保存至关重要，进一步支持未来的异地工作。刺sparganophyllum（伞形科）是一家全球极度濒危植物物种特有的ciénega西南北美的湿地。支持斑节大肠埃希菌的原位和非原位保护工作，我们询问（i）吸收后，胚：种子（E：S）的比率如何随时间变化；（ii）在暴露于冷（5°C）和热（25°C）的不同时期下，发芽如何反应赤霉素的分层和浓度（GA ₃）。通过回答这些问题，可以（iii）推断出休眠类别，并且（iv）表现出哪种存储行为类别？为了回答这些问题，我们从亚利桑那州剩余的少数野生种群之一中收集了种子。我们测量了胚胎的生长并测试了冷（0-18周）和暖（0和4周）分层以及0-1000 ppm赤霉素对发芽的影响。我们还测试了低温（-80°C）干燥（〜20％平衡相对湿度）干燥对发芽的影响。我们发现（i）胚在发芽前在种子内生长；（ii）与对照相比，冷分层至少持续6周，发芽增加，而热分层则没有效果；（iii）1000 ppm的GA ₃发芽成功率最高；（iv）因此该物种表现出形态生理休眠；（v）种子是正统的，因此可以使用常规的保存方法保存。这些信息将有助于管理人员进行对原地再引入和恢复项目至关重要的鼠尾草大肠埃希菌的繁殖，而种子库则是该物种保藏的至关重要的非原生境保护策略。