Data from: Similarity in G matrix structure among natural populations of Arabidopsis lyrata

Understanding the stability of the G matrix in natural populations is fundamental for predicting evolutionary trajectories, yet, the extent of its spatial variation and how this impacts responses to selection remain open questions. With a nested paternal half-sib crossing design and plants grown in a field experiment, we examined differences in the genetic architecture of flowering time, floral display and plant size among four Scandinavian populations of Arabidopsis lyrata. Using a multivariate Bayesian framework, we compared the size, shape and orientation of G matrices and assessed their potential to facilitate or constrain trait evolution. Flowering time, floral display and rosette size varied among populations and significant additive genetic variation within populations indicated potential to evolve in response to selection. Yet, some characters, including flowering start and number of flowers, may not evolve independently because of genetic correlations. Using a multivariate framework, we found few differences in the genetic architecture of traits among populations. G matrices varied mostly in size rather than shape or orientation. Differences in multivariate responses to selection predicted from differences in G were small, suggesting overall matrix similarity and shared constraints to trait evolution among populations.

解析自然种群中G矩阵（G matrix）的稳定性，是预测演化轨迹的核心基础，但目前G矩阵的空间变异程度及其对选择响应的影响机制仍为未决的科学问题。本研究采用嵌套式父本半同胞杂交设计，并结合田间种植实验，对4个北欧种群的 lyrate 拟南芥（Arabidopsis lyrata）的开花时间、花展示及植株大小的遗传架构差异展开了分析。本研究借助多变量贝叶斯框架，对比了不同种群G矩阵的规模、形态与取向，并评估了其对性状演化的促进或限制作用。结果显示，各种群间的开花时间、花展示及莲座大小均存在显著差异；种群内检测到的显著加性遗传变异，表明这些性状具备响应选择而演化的潜力。然而，受遗传相关性影响，包括始花期与花朵数量在内的部分性状可能无法独立演化。通过多变量框架分析，本研究发现不同种群间的性状遗传架构差异极小：G矩阵的差异主要体现为规模维度的不同，而非形态或取向的差异。基于G矩阵差异所预测的多变量选择响应差异同样较为有限，这表明各种群间的G矩阵整体相似，且面临共同的性状演化限制。