Fine mapping of the Co gene and development of DNA markers controlling columnar growth habit in apple

苹果品种‘Wijcik’是‘McIntosh’的柱状突变体。“Wijcik”的柱状生长习性的特点是紧凑的节间和减少侧枝生长，并控制一个单一的显性基因，Co，连锁群10。本研究通过精细定位的方法，筛选出3个与Co共分离的SSR标记（Mdo.chr10.12，10.13和10.14）。Mdo.chr10.12和10.14非常适合于标记辅助选择，因为与Co连锁的等位基因的大小与当前苹果育种种质的共同祖先中发现的等位基因的大小不同。我们在SSR标记11-1和14-3之间划定了Co区域，并在Co区域鉴定了插入突变。

Apple cultivar 'Wijcik' is a columnar mutant of 'McIntosh'. Columnar growth habit of 'Wijcik' is characterized by compaction of the internodes and reduced lateral shoot growth, and controlled by a single dominant gene, Co, on linkage group 10. In this study, we identified three SSR markers (Mdo.chr10.12, 10.13 and 10.14) that co-segregated with Co by fine mapping. Mdo.chr10.12 and 10.14 are well suited for marker-assisted selection because the sizes of the alleles linked to Co are different from those found in common ancestors of current apple breeding germplasm. We delimited the Co region between SSR markers 11-1 and 14-3, and identified an insertion mutation in the Co region.