Plant Pathology and Plant-Microbe Biology Section, Cornell University, Geneva, NY, 14456, USA.
Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy.
Sci Rep. 2020 Oct 1;10(1):16317. doi: 10.1038/s41598-020-73284-w.
Development of apple (Malus domestica) cultivars resistant to fire blight, a devastating bacterial disease caused by Erwinia amylovora, is a priority for apple breeding programs. Towards this goal, the inactivation of members of the HIPM and DIPM gene families with a role in fire blight susceptibility (S genes) can help achieve sustainable tolerance. We have investigated the genomic diversity of HIPM and DIPM genes in Malus germplasm collections and used a candidate gene-based association mapping approach to identify SNPs (single nucleotide polymorphisms) with significant associations to fire blight susceptibility. A total of 87 unique SNP variants were identified in HIPM and DIPM genes across 93 Malus accessions. Thirty SNPs showed significant associations (p < 0.05) with fire blight susceptibility traits, while two of these SNPs showed highly significant (p < 0.001) associations across two different years. This research has provided knowledge about genetic diversity in fire blight S genes in diverse apple accessions and identified candidate HIPM and DIPM alleles that could be used to develop apple cultivars with decreased fire blight susceptibility via marker-assisted breeding or biotechnological approaches.
培育抗火疫病（由欧文氏菌引起的破坏性细菌性疾病）的苹果（Malus domestica）品种是苹果育种计划的重点。为此，失活与火疫病易感性（S 基因）相关的 HIPM 和 DIPM 基因家族成员有助于实现可持续的耐受性。我们研究了 HIPM 和 DIPM 基因在苹果种质资源中的基因组多样性，并采用基于候选基因的关联作图方法鉴定与火疫病易感性显著相关的 SNPs（单核苷酸多态性）。在 93 个苹果品种中，HIPM 和 DIPM 基因共鉴定出 87 个独特的 SNP 变异。30 个 SNP 与火疫病易感性表现出显著关联（p<0.05），其中两个 SNP 在两年的不同时间点均表现出高度显著的关联（p<0.001）。这项研究提供了有关不同苹果品种中与火疫病相关的 S 基因遗传多样性的知识，并鉴定出候选的 HIPM 和 DIPM 等位基因，可用于通过标记辅助选择或生物技术方法培育降低火疫病易感性的苹果品种。
