Data from: Adaptive potential of ash (Fraxinus excelsior) populations against the novel emerging pathogen Hymenoscyphus pseudoalbidus

An emerging infectious pathogen Hymenoscyphus pseudoalbidus has spread across much of Europe within recent years causing devastating damage on European common ash trees (Fraxinus excelsior) and associated plant communities. The present study demonstrates the presence of additive genetic variation in susceptibility of natural F. excelsior populations to the new invasive disease. We observe high levels of additive variation in the degree of susceptibility with relatively low influence of environmental factors (narrow sense heritability = 0.37-0.52). Most native trees are found highly susceptible, and we estimate that only around 1% has the potential of producing offspring with expected crown damage of less than 10% under the present disease pressure. The results suggest that the presence of additive genetic diversity in natural F. excelsior populations can confer the species with important ability to recover, but that low resistance within natural European populations is to be expected due to a low frequency of the hypo-sensitive trees. Large effective population sizes will be required to avoid genetic bottlenecks. The role of artificial selection and breeding for protection of the species is discussed based on the findings.

一种新型传染性病原菌——假白蜡盘菌（Hymenoscyphus pseudoalbidus）近年来已在欧洲大部分地区蔓延，对欧洲白蜡树（Fraxinus excelsior）及其伴生植物群落造成毁灭性破坏。本研究证实，天然欧洲白蜡树种群对这种新入侵病害的易感性存在加性遗传变异。研究观察到，易感性程度存在高水平的加性变异，且环境因素的影响相对较低（狭义遗传力=0.37~0.52）。多数本土树木表现为高度易感，经估算，在当前病害压力下，仅约1%的个体有可能产生预期冠部损伤低于10%的后代。研究结果表明，天然欧洲白蜡树种群中存在的加性遗传多样性可赋予该物种重要的恢复能力，但由于低敏感个体的频率极低，欧洲天然种群整体抗性偏低的情况在所难免。需维持较大的有效种群规模，以避免遗传瓶颈效应。本研究基于上述发现，探讨了人工选择与育种在保护该物种中的作用。