Apple is considered the most commonly grown fruit crop in temperate regions that brings great economic profits to fruit growers. Dwarfing rootstocks have been extensively used in apple breeding as well as commercial orchards, but the molecular and genetic basis of scion dwarfing and other morphological traits induced by them is still unclear. At present, we report a genetic map of Malusdomestica × Malus baccata with high density. The F₁ population was sequenced by a specific length amplified fragment (SLAF). In the genetic map, 5064 SLAF markers spanning 17 linkage groups (LG) were included. Dwarf-related and other phenotypic traits of the scion were evaluated over a 3-year growth period. Based on quantitative trait loci (QTL) evaluation of plant height and trunk diameter, two QTL clusters were found on LG 11, which exhibited remarkable influences on dwarfing of the scion. In this analysis, QTL DW2, which was previously reported as a locus that controls dwarfing, was confirmed. Moreover, three novel QTLs for total flower number and branching flower number were detected on LG2 and LG4, exhibited the phenotypic variation that has been explained by QTL ranging from 8.80% to 34.80%. The findings of the present study are helpful to find scion dwarfing and other phenotypes induced by rootstock in the apple.

苹果被认为是温带地区最常见的水果作物，为水果种植者带来了巨大的经济利润。矮化砧木已广泛用于苹果育种和商业果园，但其诱导的接穗矮化和其他形态性状的分子和遗传基础仍不清楚。目前，我们报告了高密度的Malusdomestica  ×  Malus baccata的遗传图谱。F ₁通过特定长度的扩增片段（SLAF）对种群进行测序。在遗传图谱中，包括了跨越 17 个连锁群 (LG) 的 5064 个 SLAF 标记。在 3 年的生长期内评估了接穗的矮化相关性状和其他表型性状。基于株高和树干直径的数量性状位点（QTL）评估，在LG 11上发现了两个QTL簇，对接穗矮化有显着影响。在本次分析中，QTL DW2，之前被报道为控制矮化的基因座，得到了证实。此外，在 LG2 和 LG4 上检测到三个新的总花数和分枝花数 QTL，表现出由 QTL 解释的表型变异，范围从 8.80% 到 34.80%。本研究结果有助于发现苹果砧木引起的接穗矮化等表型。