Section of Ecology, Department of Biology, University of Turku, Turku, Finland.
J Chem Ecol. 2012 Jul;38(7):902-13. doi: 10.1007/s10886-012-0148-0. Epub 2012 Jun 9.
Previous studies of mountain birch (Betula pubescens spp. czerepanovii) repeatedly have found differences between individual trees in herbivory-related traits, but rarely have yielded estimates of the additive genetic variation of these traits or of their relationship to habitat. We used thirty-year-old birch half-sibs in a northern common garden to estimate the effect of genetics and local microhabitat on resistance-related traits. Genetic estimates of foliar chemistry have been studied only rarely with trees as old as these. Moth performance (Epirrita autumnata), rust (Melampsoridium betulinum) incidence levels, and the general level of natural herbivory damage to individual trees were used as direct measures of birch resistance. Chemical resistance-related traits in plant chemistry included 15 individual phenolics, 16 amino acids, and phenoloxidase activities in the foliage. We also followed birch phenology and growth. Our results show that the genotype of the birch was the most important determinant of phenolic composition and phenoloxidase activity, but that amino acid levels were best explained by the microhabitat of the birch. We also found that the phenology of the birch had a high heritability, although its variation was low. Our results reveal rich genetic variation in birch chemistry.
先前的研究表明，高山桦（Betula pubescens spp. czerepanovii）个体之间在与食草相关的特征上存在差异，但很少能估计出这些特征的加性遗传变异或它们与栖息地的关系。我们使用 30 岁的桦树半同胞在北方共同花园中，估计遗传和局部微生境对抗性相关特征的影响。像这样年龄的树木，对叶化学的遗传估计研究得很少。飞蛾表现（Epirrita autumnata）、锈病（Melampsoridium betulinum）发病率水平以及个体树木受到的自然食草损害的一般水平，都被用作桦树抗性的直接衡量标准。植物化学中的化学抗性相关特征包括 15 种酚类化合物、16 种氨基酸和叶中的酚氧化酶活性。我们还跟踪了桦树物候和生长。我们的研究结果表明，桦树的基因型是酚类化合物组成和酚氧化酶活性的最重要决定因素，但氨基酸水平最好由桦树的小生境来解释。我们还发现，桦树的物候学具有较高的遗传力，尽管其变异程度较低。我们的研究结果揭示了桦树化学中丰富的遗传变异。
