Avanzi Camilla, Heer Katrin, Büntgen Ulf, Labriola Mariaceleste, Leonardi Stefano, Opgenoorth Lars, Piermattei Alma, Urbinati Carlo, Vendramin Giovanni Giuseppe, Piotti Andrea
Institute of Biosciences and Bioresources, National Research Council of Italy, Via Madonna del Piano 10, 50019, Sesto Fiorentino (Firenze), Italy.
Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 11/A, 43124, Parma, Italy.
Heredity (Edinb). 2020 Jun;124(6):685-698. doi: 10.1038/s41437-020-0305-0. Epub 2020 Mar 16.
Quantifying the individual reproductive success and understanding its determinants is a central issue in evolutionary research for the major consequences that the transmission of genetic variation from parents to offspring has on the adaptive potential of populations. Here, we propose to distil the myriad of information embedded in tree-ring time series into a set of tree-ring-based phenotypic traits to be investigated as potential drivers of reproductive success in forest trees. By using a cross-disciplinary approach that combines parentage analysis and a thorough dendrophenotypic characterisation of putative parents, we assessed sex-specific relationships between such dendrophenotypic traits (i.e., age, growth rate and parameters describing sensitivity to climate and to extreme climatic events) and reproductive success in Norway spruce. We applied a full probability method for reconstructing parent-offspring relationships between 604 seedlings and 518 adult trees sampled within five populations from southern and central Europe. We found that individual female and male reproductive success was positively associated with tree growth rate and age. Female reproductive success was also positively influenced by the correlation between growth and the mean temperature of the previous vegetative season. Overall, our results showed that Norway spruce individuals with the highest fitness are those who are able to keep high-growth rates despite potential growth limitations caused by reproductive costs and climatic limiting conditions. Identifying such functional links between the individual ecophysiological behaviour and its evolutionary gain would increase our understanding on how natural selection shapes the genetic composition of forest tree populations over time.
量化个体繁殖成功率并了解其决定因素是进化研究中的核心问题，因为从亲本到后代的遗传变异传递对种群的适应潜力具有重大影响。在此，我们建议将树轮时间序列中包含的大量信息提炼为一组基于树轮的表型性状，作为林木繁殖成功的潜在驱动因素进行研究。通过采用一种跨学科方法，将亲子关系分析与对假定亲本的全面树轮表型特征相结合，我们评估了这些树轮表型性状（即年龄、生长速率以及描述对气候和极端气候事件敏感性的参数）与挪威云杉繁殖成功率之间的性别特异性关系。我们应用全概率方法重建了来自欧洲南部和中部五个种群的604株幼苗与518株成年树之间的亲子关系。我们发现，个体雌雄性繁殖成功率均与树木生长速率和年龄呈正相关。雌性繁殖成功率还受到生长与前一个生长季平均温度之间相关性的正向影响。总体而言，我们的结果表明，适应性最强的挪威云杉个体是那些尽管因繁殖成本和气候限制条件导致潜在生长受限，但仍能保持高生长速率的个体。确定个体生态生理行为与其进化收益之间的这种功能联系，将增进我们对自然选择如何随时间塑造林木种群遗传组成的理解。
