IFAPA, Centro 'Alameda del Obispo', Mejora y Biotecnologia, Avenida Menendez Pidal, s/n, 14080, Córdoba, Spain.
Theor Appl Genet. 2013 Oct;126(10):2521-32. doi: 10.1007/s00122-013-2152-3. Epub 2013 Jul 16.
Blackberry primocane fruiting, fruiting on first-year canes, has the potential to expand blackberry production both seasonally and geographically. The incorporation of the primocane-fruiting trait into cultivars with desirable horticultural attributes is challenging due to its recessive nature and tetrasomic inheritance. Molecular marker-assisted selection has high potential to facilitate incorporation, because breeders already use morphological marker-assisted selection of seedlings without marginal cotyledonary hairs to identify progeny that will be thornless when mature. The development of a genetic linkage map with these two traits is the first step to utilizing molecular markers in breeding for thornless primocane-fruiting blackberry cultivars. A full-sib family segregating for thornlessness and primocane fruiting, from a cross between 'APF-12' and 'Arapaho', was used to construct the first genetic map of tetraploid blackberry. Segregation patterns of several dominant markers and the two phenotypic traits fit those expected uniquely with tetrasomic inheritance (e.g., 5:1, 11:1 and 35:1). Some loci showed significant double reduction frequencies, but genotypes that could have originated only from double reduction were not found. The map consists of seven linkage groups (LG) in each parent, consistent with the basic number of chromosomes (2n = 4x = 28). Naming of LG1-LG6 followed that of the recently revised system for raspberry using SSR markers in common between blackberry and raspberry, and LG7 was tentatively defined by default. The loci controlling primocane fruiting and thornlessness were not linked to each other; thornless/thorny, the S Locus, was mapped on LG4, and the primocane-/floricane-fruiting locus, named in this work the F Locus, on LG7.
黑莓一年生结果，即在当年生的新枝上结果，具有扩大黑莓季节性和地理种植范围的潜力。由于其隐性和四倍体遗传特性，将一年生结果特性纳入具有理想园艺特性的品种中具有挑战性。分子标记辅助选择具有很高的应用潜力，因为育种者已经在使用无边缘子叶的形态标记辅助选择幼苗来鉴定成熟时无刺的后代。开发具有这两个特性的遗传连锁图谱是在无刺一年生结果黑莓品种选育中利用分子标记的第一步。利用‘APF-12’和‘Arapaho’杂交产生的、分离有无刺和一年生结果特性的全同胞家系，构建了四倍体黑莓的第一张遗传图谱。几个显性标记和两个表型性状的分离模式符合四倍体遗传的独特预期（例如，5:1、11:1 和 35:1）。一些位点显示出显著的双交换频率，但没有发现只能来自双交换的基因型。图谱由每个亲本的七个连锁群（LG）组成，与染色体的基本数目（2n=4x=28）一致。LG1-LG6 的命名遵循最近修订的基于 SSR 标记的覆盆子分类系统，该系统在黑莓和覆盆子之间通用，LG7 暂定为默认命名。控制一年生结果和无刺的位点彼此不连锁；无刺/有刺的 S 位点被映射到 LG4 上，而在这项工作中命名的一年生结果/二年生结果位点 F 位点被映射到 LG7 上。
