Zephyranthes tubispathais an ornamental species distributed along several countries of South America. Although it can be multiplied through bulbs or scales, seed germination is a simpler and more cost-effective process. Temperature plays a major role in the control of germination; however, its effect has been scarcely investigated in this species. In the present work, we characterized the germination responses ofZ. tubispathaseeds to different temperatures and analyzed the role of key components of the antioxidant metabolism and phytohormones in their control. Seeds showed an optimal temperature range for germination between 14 and 20°C, with higher temperatures (HTs) being progressively inhibitory. While germination was almost nil above 28°C, it could be recovered after transferring the seeds to 20°C, suggesting that thermoinhibition was the underlying phenomenon. The duration of the HT incubation period affected both the time to germination onset and the germination rate at 20°C. Similarly, the activity of antioxidant enzymes, the production of reactive oxygen species in the embryo and the sensitivity to some germination promoters varied depending on the duration of the HT treatment. The addition of 20 μM fluridone was sufficient to recover germination dynamics as in the control treatment when given after a long-term incubation period (25 d) at HT. Ethephon supply was more effective than gibberellins to suppress thermoinhibition, suggesting that changes in the balance and/or sensitivity to ethylene and abscisic acid over time play an important role in the regulation of germination responses to thermal cues in this species.

中文翻译：

---

Zephyranthes tubispathase 种子在不同热条件下的萌发反应以及抗氧化代谢和几种植物激素在其控制中的作用

和风是一种观赏物种，分布于南美洲的几个国家。虽然它可以通过球茎或鳞片繁殖，但种子发芽是一个更简单且更具成本效益的过程。温度在控制发芽方面起着重要作用；然而，它的影响在这个物种中几乎没有被研究过。在目前的工作中，我们描述了发芽反应Z. tubispatha种子对不同温度的影响，并分析了抗氧化代谢和植物激素的关键成分在其控制中的作用。种子发芽的最佳温度范围在 14 到 20°C 之间，较高的温度 (HT) 会逐渐抑制。虽然在 28°C 以上几乎没有发芽，但在将种子转移到 20°C 后发芽可以恢复，这表明热抑制是潜在的现象。HT 孵育期的持续时间影响发芽开始的时间和 20°C 下的发芽率。同样，抗氧化酶的活性、胚胎中活性氧的产生以及对某些发芽促进剂的敏感性也因 HT 处理的持续时间而异。当在 HT 长期孵育期（25 天）后给予时，添加 20 μM 氟尿酮足以恢复发芽动力学，如对照处理。乙烯利供应比赤霉素更有效地抑制热抑制，表明平衡和/或对乙烯和脱落酸的敏感性随时间的变化在调节该物种对热信号的发芽反应中起重要作用。