Park Girim, Shahwar Durre, Jang Gaeun, Shin Jagyeong, Kwon Gibeom, Kim Younjae, Hong Chang Oh, Jin Bingkui, Kim Hoytaek, Lee Oakjin, Park Younghoon
Department of Horticultural Bioscience, Pusan National University, Miryang, Republic of Korea.
Partner Seeds Co., Ltd., Gimje, Republic of Korea.
Front Genet. 2023 Sep 19;14:1256627. doi: 10.3389/fgene.2023.1256627. eCollection 2023.
The flesh color of watermelon is an important trait that is determined by carotenoid composition and affects consumers' fruit desirability. Although a complete dominant control by locus () for canary yellow flesh (CY) over red flesh has been reported, red and CY colors frequently appear as a mixed pattern in the same flesh (incomplete canary yellow, ICY) in F and inbred lines carrying dominant alleles. Therefore, we examined the genetic control of the mixed color pattern in ICY using whole-genome resequencing of three ICY (ICY group) and three CY inbred lines (CY group), as well as genetic linkage mapping of an F population. The segregation pattern in 135 F plants indicated that CY is controlled by a single locus (named ) dominant over ICY. The whole-genome resequencing of ICY and CY inbred lines revealed an ICY/CY-specific region of approximately 27.60-27.88 Mb on Chr. 2 that was polymorphic between the ICY and CY groups. Our genetic map, using nine cleaved amplified polymorphic sequence markers developed based on the single-nucleotide polymorphisms from the ICY/CY-specific region, confirmed that is located on Chr. 2 and cosegregated with the marker (M7) derived from a non-synonymous single-nucleotide polymorphism of the pentatricopeptide repeat (PPR) gene (, ). Additionally, 27 watermelon inbred lines of ICY, CY, and red flesh were evaluated using previously reported ( locus)-based markers and our locus-linked -based marker (M7). As a result, dominant alleles at the locus were required to produce CY, in addition to dominant alleles at the locus, while a recessive homozygous genotype at the locus gave the red flesh irrespective of the genotype at the locus. Using a -based cleaved amplified polymorphic sequence developed in this study and -based markers, watermelon cultivars with CY, ICY, and red flesh could be successfully discerned, implying that the combined use of these markers will be efficient for marker-assisted selection of flesh color in watermelon breeding.
西瓜的果肉颜色是一个重要性状，由类胡萝卜素组成决定，并影响消费者对果实的喜好程度。尽管已有报道称，在控制金丝雀黄色果肉（CY）对红色果肉方面，存在一个位点（）的完全显性控制，但在携带显性等位基因的F1和自交系中，红色和CY颜色经常在同一果肉中呈现混合模式（不完全金丝雀黄色，ICY）。因此，我们利用三个ICY（ICY组）和三个CY自交系（CY组）的全基因组重测序以及一个F2群体的遗传连锁图谱，研究了ICY中混合颜色模式的遗传控制。135株F2植株的分离模式表明，CY由一个单一位点（命名为）控制，对ICY呈显性。ICY和CY自交系的全基因组重测序揭示了在第2号染色体上一个约27.60 - 27.88 Mb的ICY/CY特异性区域，该区域在ICY组和CY组之间存在多态性。我们的遗传图谱使用了基于ICY/CY特异性区域单核苷酸多态性开发的9个酶切扩增多态性序列标记，证实位于第2号染色体上，并与来自五肽重复（PPR）基因（，）非同义单核苷酸多态性的标记（M7）共分离。此外，利用先前报道的基于（位点）的标记和我们基于位点连锁的标记（M7），对27个ICY、CY和红色果肉的西瓜自交系进行了评估。结果表明，除了位点的显性等位基因外，还需要位点的显性等位基因才能产生CY，而位点的隐性纯合基因型无论位点的基因型如何都产生红色果肉。利用本研究开发的基于的酶切扩增多态性序列和基于的标记，可以成功区分具有CY、ICY和红色果肉的西瓜品种，这意味着这些标记的联合使用将有效地用于西瓜育种中果肉颜色的标记辅助选择。
