Knowledge about seed germination ecology is necessary for development of protocols for in ex situ conservation and in situ restoration of rare species. Here we investigate the effect of temperature, light, GA3 and cold storage in the germination niche of Saxifraga italica (Saxifragaceae), and endemic species of Central Apennines (Italy). Several temperatures, both in dark and light conditions, and the effect of pre-chilling (60 days at 5°C) were investigated. Light was varied by changing photon flux, both in intensity and duration. The intensity of light was tested from 1.28 to 26.87 μmol (photon)·m−2·s−1, and pre-treatment with light was carried out by exposing seeds for 1, 2, 4, 8, 24 and 48 h at the beginning of the germination test. Finally, the effects of GA3 at two different concentrations. 250 ppm and 500 ppm, was tested. The results show that the species under study produce small non-dormant seeds germinating only with long-term light stimulation or with GA3. The requirement for light could be substituted by gibberellins but not by pre-chilling, as this species germinating only when on the soil surface was exposed to light and without competition. Thus, in accordance with the species distribution and life strategies, the germination niche highlights that for this species light is a fundamental factor promoting germination.

中文翻译：

---

虎耳草种子生态学：光、温度和赤霉酸的影响

有关种子萌发生态学的知识对于制定稀有物种的异地保护和就地恢复协议是必要的。在这里，我们研究了温度、光照、GA3 和冷藏对虎耳草（虎耳草科）和中亚平宁山脉（意大利）特有物种的萌发生态位的影响。研究了黑暗和光照条件下的几种温度以及预冷（5°C 下 60 天）的影响。通过改变光子通量（强度和持续时间）来改变光。测试光强度为 1.28 至 26.87 μmol（光子）·m-2·s-1，并通过将种子暴露于 1、2、4、8、24 和 48 小时进行光预处理。发芽试验的开始。最后，GA3 在两种不同浓度下的影响。测试了 250 ppm 和 500 ppm。结果表明，所研究的物种产生仅在长期光刺激或 GA3 下发芽的小型非休眠种子。对光的要求可以用赤霉素代替，但不能用预冷代替，因为该物种只有在土壤表面暴露于光且没有竞争时才会发芽。因此，根据物种分布和生活策略，萌发生态位强调，对于该物种而言，光是促进萌发的基本因素。