Kunihisa Miyuki, Takita Yuki, Yamaguchi Nanako, Okada Hatsuhiko, Sato Mamoru, Komori Sadao, Nishitani Chikako, Terakami Shingo, Yamamoto Toshiya
Institute of Fruit Tree and Tea Science, NARO, 2-1 Fujimoto, Tsukuba, Ibaraki 305-8605, Japan.
Fukushima Agricultural Technology Center, 1 Dan-no-higashi, Hirano, Iizaka, Fukushima, Fukushima 960-0231, Japan.
Breed Sci. 2019 Sep;69(3):410-419. doi: 10.1270/jsbbs.18197. Epub 2019 Jul 4.
Apple is an economically important crop, and various approaches to genetic analysis in breeding programs have been attempted, including the production of doubled haploid (DH) lines, which are genetically homozygous. In this study, we used a DH line for QTL analyses, for the first time in a fruit tree, expecting it to simplify the analysis of the inheritance of quantitative traits and thus to enhance QTL detection power. Using an F population from 'Prima' × 'Apple Chukanbohon 95P6' (DH), we constructed a genetic map of 'Prima', and identified 19 QTLs for 13 traits. These QTLs had comparatively high LOD scores and explained a large part of the variation of the phenotypes. In particular, acidity, juice browning, and skin splitting clearly segregated at a 1:1 ratio, consistent with the segregation of the alleles at the detected QTLs in linkage group 16; these traits appeared to be regulated by single genes, despite general consideration that they are quantitative traits. Using this simple genetic composition of the F population, we concluded that the skin splitting of apple fruit has recessive inheritance, and that the allele for splitting is tightly linked with those for high acidity and low juice browning in 'Prima'.
苹果是一种具有重要经济价值的作物，人们已经尝试了多种育种计划中的遗传分析方法，包括生产双单倍体（DH）系，其基因是纯合的。在本研究中，我们首次在果树中使用DH系进行QTL分析，期望它能简化数量性状遗传的分析，从而提高QTL检测能力。利用‘Prima’בApple Chukanbohon 95P6’（DH）的F群体，我们构建了‘Prima’的遗传图谱，并鉴定出13个性状的19个QTL。这些QTL具有相对较高的LOD值，解释了大部分表型变异。特别是，酸度、果汁褐变和果皮开裂明显以1:1的比例分离，这与连锁群16中检测到的QTL上等位基因的分离一致；尽管通常认为这些是数量性状，但这些性状似乎受单个基因调控。利用F群体这种简单的遗传组成，我们得出结论，苹果果实的果皮开裂具有隐性遗传，并且在‘Prima’中，开裂等位基因与高酸度和低果汁褐变的等位基因紧密连锁。
