Presence of natural genetic resistance in Fraxinus excelsior (Oleraceae) to Chalara fraxinea (Ascomycota): an emerging infectious disease
Presence of natural genetic resistance in Fraxinus excelsior (Oleraceae) to Chalara fraxinea (Ascomycota): an emerging infectious disease
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DOI：
10.1038/hdy.2010.119
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发表时间：
2011-05-01
期刊：
影响因子：
3.8
通讯作者：
Kjaer, E. D.
中科院分区：
文献类型：
--
作者：
McKinney, L. V.;Nielsen, L. R.;Kjaer, E. D.
精华白蜡树是一种原产于欧洲的普通白蜡树，受到最近发现的一种病原真菌Chalara fraxinea的威胁，该真菌会对欧洲各地的白蜡树造成广泛的损害。在丹麦，大多数林木受到严重影响，导致许多树木树冠枯萎。然而，单株树木表现出的症状明显较少。在这项研究中，通过估计自然种群中存在的固有抗性来评估新出现的传染病对丹麦本土白蜡树的影响。从2007年到2009年，在两个不同的地点用39个代表当地精益树的选定无性系的嫁接株对病害症状进行了评估。观察到对华支睾吸虫感染的易感性有很强的遗传变异。没有遗传或地理结构可以解释这种差异，但观察到与叶片衰老有很强的遗传相关性。结果表明，在丹麦白蜡树种群中，有一小部分树木对这种损害具有很强的抵抗力。虽然这一比例可能太低，无法避免大多数天然或管理的白蜡林的种群崩溃，但在天然林分中观察到的对新出现的传染病的假定抵抗力的存在可能具有进化重要性。这为未来通过自然或人工选择维持物种提供了前景，有利于保持健康的个体。《遗传》(2011)106788-797；doi：10.1038/hdy.2010.119；2010年9月8日在线发布
Fraxinus excelsior, common ash native to Europe, is threatened by a recently identified pathogenic fungus Chalara fraxinea, which causes extensive damage on ash trees across Europe. In Denmark, most stands are severely affected leaving many trees with dead crowns. However, single trees show notably fewer symptoms. In this study, the impact of the emerging infectious disease on native Danish ash trees is assessed by estimating presence of inherent resistance in natural populations. Disease symptoms were assessed from 2007 to 2009 at two different sites with grafted ramets of 39 selected clones representing native F. excelsior trees. A strong genetic variation in susceptibility to C. fraxinea infections was observed. No genetic or geographic structure can explain the differences, but strong genetic correlations to leaf senescence were observed. The results suggest that a small fraction of trees in the Danish population of ash possess substantial resistance against the damage. Though this fraction is probably too low to avoid population collapse in most natural or managed ash forests, the observed presence of putative resistance against the emerging infectious disease in natural stands is likely to be of evolutionary importance. This provides prospects of future maintenance of the species through natural or artificial selection in favour of remaining healthy individuals. Heredity (2011) 106, 788-797; doi:10.1038/hdy.2010.119; published online 8 September 2010