School of Forestry, Northern Arizona University, 200 E. Pine Knoll, Flagstaff, AZ, 86011, USA.
Dorena Genetic Resource Center, USDA Forest Service, Cottage-Grove, OR, 97424, USA.
Plant J. 2020 Oct;104(2):365-376. doi: 10.1111/tpj.14928. Epub 2020 Jul 28.
The genomic architecture and molecular mechanisms controlling variation in quantitative disease resistance loci are not well understood in plant species and have been barely studied in long-generation trees. Quantitative trait loci mapping and genome-wide association studies were combined to test a large single nucleotide polymorphism (SNP) set for association with quantitative and qualitative white pine blister rust resistance in sugar pine. In the absence of a chromosome-scale reference genome, a high-density consensus linkage map was generated to obtain locations for associated SNPs. Newly discovered associations for white pine blister rust quantitative disease resistance included 453 SNPs involved in wide biological functions, including genes associated with disease resistance and others involved in morphological and developmental processes. In addition, NBS-LRR pathogen recognition genes were found to be involved in quantitative disease resistance, suggesting these newly reported genes are qualitative genes with partial resistance, they are the result of defeated qualitative resistance due to avirulent races, or they have epistatic effects on qualitative disease resistance genes. This study is a step forward in our understanding of the complex genomic architecture of quantitative disease resistance in long-generation trees, and constitutes the first step towards marker-assisted disease resistance breeding in white pine species.
在植物物种中,控制数量疾病抗性基因座变异的基因组结构和分子机制尚未得到很好的理解,在长世代树木中几乎没有研究过。数量性状位点作图和全基因组关联研究相结合,测试了大量单核苷酸多态性 (SNP) 与糖松对白松疱锈病的数量和定性抗性的关联。在没有染色体规模参考基因组的情况下,生成了高密度共识连锁图谱,以获得关联 SNP 的位置。新发现的白松疱锈病数量疾病抗性关联包括 453 个 SNP,涉及广泛的生物学功能,包括与抗性相关的基因和其他涉及形态和发育过程的基因。此外,还发现 NBS-LRR 病原体识别基因参与数量疾病抗性,表明这些新报告的基因是具有部分抗性的定性基因,它们是由于无毒菌株导致定性抗性失败的结果,或者它们对定性疾病抗性基因具有上位效应。这项研究是我们对白松树种数量疾病抗性复杂基因组结构理解的一个进步,也是在白松种中进行标记辅助抗性育种的第一步。