Division of Basic Research, Institute of Crop Science, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan.
Division of Lowland Farming Research, Kyusyu Okinawa Agricultural Research Center, National Agriculture and Food Research Organization, Chikugo, Fukuoka, Japan.
PLoS One. 2020 Mar 11;15(3):e0230326. doi: 10.1371/journal.pone.0230326. eCollection 2020.
Milling properties and flour color are essential selection criteria in soft wheat breeding. However, high phenotypic screening costs restrict selection to relatively few breeding lines in late generations. To achieve marker-based selection of these traits in early generations, we performed genetic dissection of quality traits using three doubled haploid populations that shared the high-quality soft wheat variety Kitahonami as the paternal parent. An amplicon sequencing approach allowed effective construction of well-saturated linkage maps of the populations. Marker-based heritability estimates revealed that target quality traits had relatively high values, indicating the possibility of selection in early generations. Taking advantage of Chinese Spring reference sequences, joint linkage maps of the three populations were generated. Based on the maps, multifamily quantitative trait locus (QTL) analysis revealed a total of 86 QTLs for ten traits investigated. In terms of target quality traits, 12 QTLs were detected for flour yield, and 12 were detected for flour redness (a* value). Among these QTLs, six for flour yield and nine for flour a* were segregating in more than two populations. Some relationships among traits were explained by QTL collocations on chromosomes, especially group 7 chromosomes. Ten different ideotypes with various combinations of favorable alleles for the flour yield and flour a* QTLs were generated. Phenotypes of derivatives from these ideotypes were predicted to design ideal genotypes for high-quality wheat. Simulations revealed the possibility of breeding varieties with better quality than Kitahonami.
制粉特性和面粉颜色是软小麦育种的重要选择标准。然而，高表型筛选成本限制了对后期世代中相对较少的育种群的选择。为了在早期世代实现这些性状的基于标记的选择，我们使用三个共享优质软小麦品种 Kitahonami 作为父本的双单倍体群体进行了质量性状的遗传剖析。扩增子测序方法允许有效地构建群体的高度饱和连锁图谱。基于标记的遗传力估计表明，目标质量性状具有相对较高的值，表明早期选择的可能性。利用中国春参考序列，生成了三个群体的联合连锁图谱。基于图谱，对十个性状进行了多系定量性状位点（QTL）分析，共发现 86 个 QTL。就目标质量性状而言，检测到 12 个与面粉产量相关的 QTL，以及 12 个与面粉红色度（a值）相关的 QTL。在这些 QTL 中，有 6 个与面粉产量相关，9 个与面粉 a相关，在两个以上的群体中分离。一些性状之间的关系可以通过染色体上的 QTL 共定位来解释，特别是 7 号染色体组。针对面粉产量和面粉 a* QTL 生成了十个具有不同有利等位基因组合的不同理想型。从这些理想型的衍生品种的预测表型可以设计出用于优质小麦的理想基因型。模拟表明，有可能培育出比 Kitahonami 质量更好的品种。
