Uppsala Biocentre, Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
Uppsala Biocentre, Department of Plant Biology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
Mol Ecol. 2021 Sep;30(18):4433-4447. doi: 10.1111/mec.16058. Epub 2021 Aug 5.
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.
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应对。具有讽刺意味的是，控制这一过程的遗传和分子机制还了解甚少。本研究的目的是比较挪威云杉对 Heterobasidion annosum s.s.及其同域近缘种 Heterobasidion parviporum 的抗性的遗传组成。 Heterobasidion 根腐病和茎腐病是由 Heterobasidion annosum 种复合体成员引起的挪威云杉的主要病害。使用源自中欧和北欧的挪威云杉半同胞家系进行人工接种来测量对两种病原体的抗性。使用 63,760 个全基因组外显子捕获测序 SNP 和多性状全基因组关联分析来分析抗性的遗传成分。发现两种病原体的抗性之间没有相关性；然而，在与两种病原体都具有协同或拮抗多效性的抗性性状和基因组变异之间发现了关联。此外，还发现了 Heterobasidion annosum s.s. 在树皮中的抗性的纬度梯度；来自南部纬度的树木，具有较晚的芽期和较厚的茎直径，允许更长的病变，但对于 Heterobasidion parviporum 则不是这样。总之，本研究从基因水平检测出具有多效性的基因组变异，这些变异可以解释多种疾病抗性，对于选择对两种病原体都具有抗性的树木可能有用。此外，它还强调了需要进一步研究以了解树木对多种病原体抗性性状的进化。
