We evaluated whether phytotoxic effects of the essential oil from Eucalyptus saligna Sm. leaf litter were related to its major compounds 1,8-cineole (eucalyptol) and α-pinene. Effects of the essential oil and its major compounds, combined and alone, were tested on germination and growth of the weed Eragrostis plana Ness. Volatile organic compounds (VOCs) emitted from the essential oil were determined in the airspace of Petri dishes during the experimental period. These volatile fractions were obtained by solid-phase microextraction (SPME) followed by gas-chromatography coupled to mass spectrometry (GC-MS). Effects of the oil and its major compounds were also assessed in aqueous solution on coleoptile growth of Triticum aestivum L. The essential oil showed the strongest phytotoxic effects on E. plana, followed by eucalyptol, eucalyptol + α-pinene, and α-pinene. A similar order of phytotoxicity was observed on coleoptile growth of T. aestivum. The proportion of oxygenated monoterpenes increased along the experimental period, mainly eucalyptol, and of monoterpene hydrocarbons diminished in the volatile fractions. We conclude that phytotoxicity of E. saligna leaf litter essential oil may be mainly related to eucalyptol and additive or synergistic effects of other minor compounds. Analysing VOCs emission is relevant to elucidate compounds involved in phytotoxicity of a plant species.

我们评估了来自桉树Sm的香精油是否具有植物毒性作用。凋落物与其主要化合物1,8-桉树脑（桉树油）和α-pine烯有关。测试了香精油及其主要化合物（单独和单独使用）对杂草Eragrostis Plana Ness发芽和生长的影响。在实验期间，在皮氏培养皿的空域中测定了从精油中散发的挥发性有机化合物（VOC）。通过固相微萃取（SPME），然后进行气相色谱-质谱联用（GC-MS），获得了这些挥发性部分。还评估了该油及其主要化合物在水溶液中对小麦的胚芽鞘生长的影响。L.精油对平面大肠杆菌表现出最强的植物毒性作用，其次为桉树油，桉树油+α-pine烯和α-pine烯。在小麦胚芽鞘的胚芽鞘生长中观察到了类似的植物毒性。含氧单萜的比例随实验期间的增加而增加，主要是桉树油，而挥发性成分减少的单萜碳氢化合物的比例也有所增加。我们得出的结论是，S。saligna叶凋落物精油的植物毒性可能主要与桉树油和其他次要化合物的累加或协同作用有关。分析挥发性有机化合物的排放与阐明涉及植物物种的植物毒性的化合物有关。