Rising Out of the Ashes: Additive Genetic Variation for Crown and Collar Resistance to Hymenoscyphus fraxineus in Fraxinus excelsior
Rising Out of the Ashes: Additive Genetic Variation for Crown and Collar Resistance to Hymenoscyphus fraxineus in Fraxinus excelsior
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DOI：
10.1094/phyto-11-15-0284-r
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发表时间：
2016-12-01
期刊：
影响因子：
3.2
通讯作者：
Dowkiw, Arnaud
中科院分区：
文献类型：
--
作者：
Munoz, Facundo;Marcais, Benoit;Dowkiw, Arnaud
自 20 世纪 90 年代初以来，入侵性子囊菌 Hymenoscyphus fraxineus 导致的白蜡枯死正威胁着白蜡树 (Fraxinus excelsior) 的大部分自然分布区。先前的研究报告了在田间或接种实验中，F. excelsior 的易感性遗传变异性水平显着。本研究基于 1995 年（即该病害发病前 15 年）种植的田间试验。对源自三个法国来源的 23 个开放授粉后代的 777 棵树的树冠和颈圈状态进行了监测。使用贝叶斯方法对健康状况进行建模，其中明确考虑了时空效应。树冠顶枯病具有中等的狭义遗传力（h(2) = 0.42）。这项研究首次表明，颈圈水平的抵抗力也是可遗传的（颈圈病变患病率 h(2) = 0.49，其严重程度 h(2) = 0.42），并且牙冠和颈圈症状的严重程度之间存在显着的遗传相关性（r = 0.40）。没有证据表明来源之间存在差异。检测到了家族效应，但计算个体育种值表明，大部分遗传变异存在于家族内部。与之前的报告一致，早期潮红与健康的牙冠相关。讨论了这些结果对疾病管理和育种的影响。
Since the early 1990s, ash dieback due to the invasive ascomycete Hymenoscyphus fraxineus is threatening Fraxinus excelsior in most of its natural range. Previous studies reported significant levels of genetic variability in susceptibility in F. excelsior either in field or inoculation experiments. The present study was based on a field experiment planted in 1995, 15 years before onset of the disease. Crown and collar status were monitored on 777 trees from 23 open-pollinated progenies originating from three French provenances. Health status was modeled using a Bayesian approach where spatiotemporal effects were explicitly taken into account. Moderate narrow-sense heritability was found for crown dieback (h(2) = 0.42). This study is first to show that resistance at the collar level is also heritable (h(2) = 0.49 for collar lesions prevalence and h(2) = 0.42 for their severity) and that there is significant genetic correlation (r = 0.40) between the severities of crown and collar symptoms. There was no evidence for differences between provenances. Family effects were detected, but computing individual breeding values showed that most of the genetic variation lies within families. In agreement with previous reports, early flushing correlates with healthier crown. Implications of these results in disease management and breeding are discussed.