Laboratorio de Ecología Química, Facultad de Química, Universidad de la República-Uruguay, Montevideo, Gral. Flores 2124, 11800, Uruguay.
Graduate Program in Chemistry, Facultad de Química, Universidad de la República, Montevideo, Uruguay.
J Chem Ecol. 2023 Oct;49(9-10):482-497. doi: 10.1007/s10886-023-01435-0. Epub 2023 Jul 31.
Eucalyptus species are among the most planted trees in forestry production, an ever-increasing commercial activity worldwide. Forestry expansion demands a continuous search for preventive and sanitary measures against pests and diseases. Massive application of phytosanitary products is incompatible with the forestry sector, so forest health management must be based on other principles. In this context, studies on insect plant relationships mediated by plant metabolites may contribute information relevant to plant resistance and genotype selection. In this study, we analyzed the leaf metabolome of four Eucalyptus species commonly planted in southern South America, to correlate this chemical information with feeding preference of Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae), an important pest of eucalypt plantations. Gas chromatography mass spectrometry analyses were performed on polar and non-polar leaf extracts from Eucalyptus globulus, Eucalyptus grandis, Eucalyptus robusta, and Eucalyptus tereticornis (Myrtaceae). Feeding preferences were assessed in two-choice laboratory bioassays resulting in a preference gradient of the four plant species. Moreover, a performance bioassay where we contrasted survival and development time between the most and least preferred plants, showed a clear correlation with preference both in survival and developmental time of the most susceptible nymph instar. We found that species with high or low feeding preferences differ significantly in several foliar metabolites, which may be acting as feeding stimulants or deterrents for T. peregrinus. These findings may provide useful criteria for choosing Eucalyptus genotypes when planting in bronze bug infested areas.
桉树是林业生产中种植最多的树种之一，也是全球日益增长的商业活动。林业扩张要求不断寻找针对病虫害的预防和卫生措施。大量使用植物检疫产品与林业部门不相容，因此森林健康管理必须基于其他原则。在这种情况下，研究植物代谢物介导的昆虫与植物关系可能有助于提供与植物抗性和基因型选择相关的信息。在这项研究中，我们分析了南方南美洲常见的四个桉树物种的叶片代谢组，将这种化学信息与 Thaumastocoris peregrinus（半翅目：Thaumastocoridae）的取食偏好相关联，Thaumastocoris peregrinus 是桉树种植园的重要害虫。对来自蓝桉、巨桉、粗皮桉和尾叶桉（桃金娘科）的极性和非极性叶片提取物进行气相色谱-质谱分析。在实验室双选择生物测定中评估取食偏好，得出四个植物物种的取食偏好梯度。此外，我们还进行了生存和发育时间的性能生物测定，对比了最受欢迎和最不受欢迎的植物之间的差异，结果显示与取食偏好之间存在明显的相关性，最易感的若虫龄期的生存和发育时间都存在这种相关性。我们发现，取食偏好高或低的物种在几种叶片代谢物上存在显著差异，这些代谢物可能对 T. peregrinus 起到取食刺激或抑制作用。这些发现可能为在青铜虫出没地区种植桉树提供有用的选择桉树基因型的标准。
