ABSTRACT Tree breeders are increasingly using resistance drilling (RESI) for the non-destructive assessment of wood basic density, but its application to the measurement of stem diameter at breast height (DBH) and bark thickness is less reported. Using Eucalyptus globulus progeny trials established with open-pollinated families from native trees representing 13 subraces, and adjusting bark thickness for its inherent phenotypic relationship with DBH, we: (1) quantified the genetic correlation between RESI and analogous traditional measurements of these traits; and (2) studied their genetic architecture and associations with subrace home-site climate. Significant variation was detected for all traditional and RESI-derived traits at the family and subrace level. High family and subrace-level correlations (>0.90) were found between RESI and traditional methods for all three traits. Bark thickness exhibited among the highest subrace differentiation (QST > 0.63) reported to date for E. globulus, signalling divergent selection. Increasing bark thickness was positively associated with home-site temperature annual range and seasonality. Although subrace differentiation for wood density (RESI and traditional measures) was less (QST = 0.18–0.21), a similar climate association was detected, and the subrace-level correlation with bark thickness was positive and significant (0.61–0.75). However, the non-significant correlations between bark thickness and wood density at the family level suggest that selective covariance rather than pleiotropy have caused the correlated patterns of subrace variation. Variation in bark thickness (adjusted) and wood density was independent of DBH at the family and subrace level. Given the importance of these traits, RESI provides a useful approach for non-destructive assessments for silvicultural, genetics and ecological studies of forest trees.

中文翻译：

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电阻钻在蓝桉生长、木材基本密度和树皮厚度遗传研究中的应用

摘要 树木育种者越来越多地使用电阻钻孔 (RESI) 对木材基本密度进行无损评估，但其在胸高 (DBH) 和树皮厚度测量中的应用却鲜有报道。使用蓝桉子代试验，由来自代表 13 个亚种的本地树木的开放授粉家族建立，并根据其与 DBH 的固有表型关系调整树皮厚度，我们：（1）量化了 RESI 与这些性状的类似传统测量之间的遗传相关性；(2) 研究了它们的遗传结构和与亚种家庭气候的关联。在家庭和亚种水平上检测到所有传统和 RESI 衍生性状的显着变异。高家族和亚种水平相关性（>0. 90) 在 RESI 和传统方法之间发现所有三个性状。树皮厚度在迄今为止报道的 E. globulus 最高亚种分化（QST > 0.63）中表现出，表明不同的选择。增加树皮厚度与家庭现场温度年度范围和季节性呈正相关。尽管木材密度（RESI 和传统措施）的亚种分化较小（QST = 0.18-0.21），但检测到类似的气候关联，并且亚种水平与树皮厚度的相关性为正且显着（0.61-0.75）。然而，在家庭水平上树皮厚度和木材密度之间的非显着相关性表明选择性协方差而不是多效性导致了亚种变异的相关模式。树皮厚度（调整后）和木材密度的变化与科和亚种水平的 DBH 无关。鉴于这些特性的重要性，RESI 为林木造林、遗传和生态研究的无损评估提供了一种有用的方法。