Teagasc, Crop Science Department, Oak Park, Carlow, R93 XE12, Ireland.
Wageningen University & Research (WUR), 6708 PB Wageningen, The Netherlands.
Genes (Basel). 2020 Jun 30;11(7):732. doi: 10.3390/genes11070732.
Wild potato species continue to be a rich source of genes for resistance to late blight in potato breeding. Whilst many dominant resistance genes from such sources have been characterised and used in breeding, quantitative resistance also offers potential for breeding when the loci underlying the resistance can be identified and tagged using molecular markers. In this study, F populations were created from crosses between blight susceptible parents and lines exhibiting strong partial resistance to late blight derived from the South American wild species and . Both populations exhibited continuous variation for resistance to late blight over multiple field-testing seasons. High density genetic maps were created using single nucleotide polymorphism (SNP) markers, enabling mapping of quantitative trait loci (QTLs) for late blight resistance that were consistently expressed over multiple years in both populations. In the population created with the source, QTLs for resistance consistently expressed over three years and explaining a large portion (21-47%) of the phenotypic variation were found on chromosomes 5 and 6, and a further resistance QTL on chromosome 10, apparently related to foliar development, was discovered in 2016 only. In the population created with the source, QTLs for resistance were found in over two years on chromosomes 11 and 12. For all loci detected consistently across years, the QTLs span known R gene clusters and so they likely represent novel late blight resistance genes. Simple genetic models following the effect of the presence or absence of SNPs associated with consistently effective loci in both populations demonstrated that marker assisted selection (MAS) strategies to introgress and pyramid these loci have potential in resistance breeding strategies.
野生马铃薯种仍然是马铃薯抗晚疫病育种的丰富基因来源。虽然许多来自此类来源的显性抗性基因已经被鉴定和用于育种，但当可以识别和使用分子标记标记抗性的基因座时，数量抗性也为育种提供了潜力。在这项研究中，从对晚疫病敏感的亲本与从南美野生种 和 中衍生出具有强部分抗性的亲本之间创建了 F 群体。两个群体在多个田间试验季节均表现出对晚疫病的连续抗性变化。使用单核苷酸多态性（SNP）标记创建了高密度遗传图谱，能够在两个群体中多年一致表达的晚疫病抗性数量性状基因座（QTL）进行映射。在用 来源创建的群体中，在三年中一致表达并解释大部分（21-47％）表型变异的抗性 QTL 位于染色体 5 和 6 上，在 2016 年还发现了另一个与叶片发育有关的抗性 QTL 位于染色体 10 上。在用 来源创建的群体中，在两年以上的时间里在染色体 11 和 12 上发现了抗性 QTL。对于所有在多年内一致检测到的位点，QTL 跨越已知的 R 基因簇，因此它们可能代表新的晚疫病抗性基因。在两个群体中始终存在与有效位点相关的 SNP 存在或不存在的简单遗传模型表明，在抗性育种策略中引入和聚合这些位点的标记辅助选择（MAS）策略具有潜力。
