Studies show that just over 620 non-native naturalised plant species have been recorded within the Australian rangelands, some of which have a capacity to cause significant impacts on rangeland flora and grazing activity. Although Psilocaulon granulicaule (Haw.), Schwantes is listed as a highly invasive environmental weed species, there has been no previous research into its seed ecology. Therefore, this study was conducted to investigate the effects of temperature, light, pH, water stress, heat-shock, and salinity on the germination of P. granulicaule. In this study, four temperature regimes covering four different day and night temperature variations (17–7°C, 25–15°C, 30–25°C and 40–30°C) and two light regimes (12-h light–12-h dark, 24-h dark) were investigated. The effects of pH, water stress, heat-shock and salinity were investigated, using pH buffers, polyethylene glycol solutions, three heat shock events under four temperatures and a range of NaCl solutions. These tests were conducted under the identified optimum temperature range (25/15°C) and light regime for seed germination. The results showed that both temperature and photoperiod significantly influenced the germination rate, with 94.2% germination in the 25–15°C range under a 12-h light-12-h dark regime. Higher temperatures (30–40°C) reduced seed germination to <58% germination in both light regimes (57.5%, 12-h light-12-h dark; 54.17%, 24-h dark). The highest germination rates were observed in low pH solutions, high moisture levels, low heat-shocks and low salinity. The study showed that this species is sensitive to environmental factors such as temperature, light, pH, moisture, heat shock and salinity, suggesting that these factors can be used as critical indicators to guide effective management practices to address this weed problem. Given that seeds are sensitive to radiant heat, burning could be used as a tool to effectively manage this species.

中文翻译：

---

潜在牧场杂草 Psilocaulon granulicaule 对选定环境条件的种子萌发反应

研究表明，澳大利亚牧场内记录了超过 620 种非本地归化植物物种，其中一些能够对牧场植物群和放牧活动造成重大影响。尽管 Psilocaulon granulicaule (Haw.), Schwantes 被列为高度入侵的环境杂草物种，但之前没有对其种子生态学的研究。因此，本研究旨在研究温度、光照、pH 值、水分胁迫、热激和盐度对 P. granulicaule 萌发的影响。在这项研究中，四种温度状态涵盖了四种不同的昼夜温度变化（17-7°C、25-15°C、30-25°C 和 40-30°C）和两种光照状态（12 小时光照- 12 小时黑暗，24 小时黑暗）进行了研究。研究了 pH 值、水分胁迫、热激和盐度的影响，使用 pH 缓冲液、聚乙二醇溶液、四种温度下的三种热激事件和一系列 NaCl 溶液。这些测试是在确定的最佳温度范围 (25/15°C) 和种子发芽的光照条件下进行的。结果表明，温度和光周期均显着影响发芽率，在 25-15°C 范围内 12 小时光照 - 12 小时黑暗制度下发芽率为 94.2%。在两种光照条件下（57.5%，12 小时光照 - 12 小时黑暗；54.17%，24 小时黑暗），较高的温度 (30–40°C) 将种子发芽降低至 <58%。在低 pH 值、高水分含量、低热冲击和低盐度的溶液中观察到最高的发芽率。研究表明，该物种对温度、光照、pH、水分、热休克和盐度等环境因素敏感，表明这些因素可以用作指导有效管理实践以解决这一杂草问题的关键指标。鉴于种子对辐射热很敏感，燃烧可以用作有效管理该物种的工具。