Manoharan Ranjith Kumar, Jung Hee-Jeong, Hwang Indeok, Jeong Namhee, Kho Kang Hee, Chung Mi-Young, Nou Ill-Sup
Department of Horticulture, Sunchon National University, 255, Jungang-ro, Suncheon, Jeonnam 57922 Republic of Korea.
Department of Fisheries Science, Chonnam National University, 50, Daehak-ro, Yeosu, Jeonnam 59626 Republic of Korea.
Hereditas. 2017 Jan 11;154:1. doi: 10.1186/s41065-016-0023-z. eCollection 2017.
Tomatoes provide a significant dietary source of the carotenoids, lycopene and β-carotene. During ripening, carotenoid accumulation determines the fruit colors while chlorophyll degradation. These traits have been, and continue to be, a significant focus for plant breeding efforts. Previous work has found strong evidence for a relationship between gene expression and the orange color of fleshy fruit. Other work has identified a point mutation in that impedes chlorophyll degradation and causes brown flesh color to be retained in some tomato varieties.
We crossed two inbred lines, KNY2 (orange) and KNB1 (brown) and evaluated the relationship between these genes for their effect on fruit color. Phenotypes of F2 generation plants were analyzed and a novel 'orange-brown' fruit color was identified.
We confirm two SNPs, one in and another in gene sequence, associated with segregation of 'orange-brown' fruit color in F2 generation. The carotenoid and chlorophyll content of a fleshy fruit was assessed across the different phenotypes and showed a strong correlation with expression pattern of carotenoid biosynthesis genes and SGR function. The orange-brown fruit has high β-carotene and chlorophyll. Our results provide valuable information for breeders to develop tomato fruit of a novel color using molecular markers.
番茄是类胡萝卜素、番茄红素和β-胡萝卜素的重要膳食来源。在果实成熟过程中，类胡萝卜素的积累决定了果实颜色，同时叶绿素降解。这些性状一直是植物育种工作的重要关注点。先前的研究发现了基因表达与肉质果实橙色之间存在关联的有力证据。其他研究还在某个基因中鉴定出一个点突变，该突变阻碍叶绿素降解，并导致一些番茄品种中保留褐色果肉颜色。
我们将两个自交系KNY2（橙色）和KNB1（褐色）进行杂交，并评估这些基因对果实颜色影响的关系。分析了F2代植株的表型，并鉴定出一种新的“橙褐色”果实颜色。
我们确认了两个单核苷酸多态性（SNP），一个在某个基因中，另一个在另一个基因序列中，它们与F2代“橙褐色”果实颜色的分离相关。对不同表型的肉质果实的类胡萝卜素和叶绿素含量进行了评估，结果显示其与类胡萝卜素生物合成基因的表达模式和SGR功能存在强相关性。橙褐色果实具有较高的β-胡萝卜素和叶绿素。我们的结果为育种者利用分子标记培育新型颜色的番茄果实提供了有价值的信息。
