Trees must cope with the attack of multiple pathogens, often simultaneously during their long lifespan. Ironically, the genetic and molecular mechanisms controlling this process are poorly understood. The objective of this study was to compare the genetic component of resistance in Norway spruce to Heterobasidion annosum s.s. and its sympatric congener Heterobasidion parviporum. Heterobasidion root- and stem-rot is a major disease of Norway spruce caused by members of the Heterobasidion annosum species complex. Resistance to both pathogens was measured using artificial inoculations in half-sib families of Norway spruce trees originating from central to northern Europe. The genetic component of resistance was analysed using 63,760 genome-wide exome-capture sequenced SNPs and multitrait genome-wide associations. No correlation was found for resistance to the two pathogens; however, associations were found between genomic variants and resistance traits with synergic or antagonist pleiotropic effects to both pathogens. Additionally, a latitudinal cline in resistance in the bark to H. annosum s.s. was found; trees from southern latitudes, with a later bud-set and thicker stem diameter, allowed longer lesions, but this was not the case for H. parviporum. In summary, this study detects genomic variants with pleiotropic effects which explain multiple disease resistance from a genic level and could be useful for selection of resistant trees to both pathogens. Furthermore, it highlights the need for additional research to understand the evolution of resistance traits to multiple pathogens in trees.

中文翻译：

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用一块石头杀死两个敌人？挪威云杉对两种同域病原体的抗性基因组学

树木必须应对多种病原体的攻击，通常在其漫长的生命周期中同时发生。具有讽刺意味的是，人们对控制这一过程的遗传和分子机制知之甚少。本研究的目的是比较挪威云杉与Heterobasidion annosum s抗性的遗传成分。小号_ 及其同域同系物Heterobasidion parviporum。Heterobasidion root- and stem-rot-rot 是挪威云杉的主要病害，由Heterobasidion annosum的成员引起。物种复杂。在源自中欧至北欧的挪威云杉树的半同胞家族中使用人工接种来测量对这两种病原体的抗性。使用 63,760 个全基因组外显子组捕获测序的 SNP 和多性状全基因组关联分析了抗性的遗传成分。没有发现对这两种病原体的抗性相关；然而，在基因组变异和抗性特征之间发现了对这两种病原体具有协同或拮抗多效作用的关联。此外，树皮对H. annosum s的抗性存在纬度倾向。小号_ 被找到; 来自南部纬度的树木，具有较晚的芽和较粗的茎直径，允许较长的病变，但对于H. parviporum不是这种情况. 总之，这项研究检测了具有多效性的基因组变异，这些变异从基因水平解释了多种抗病性，可用于选择对两种病原体具有抗性的树木。此外，它强调需要进一步研究以了解树木对多种病原体的抗性特征的演变。