Plant Genome. 2017 Mar;10(1). doi: 10.3835/plantgenome2016.07.0074.
Common bermudagrass has been widely used as a major warm-season turf, forage, and soil stabilization grass in the southern United States. However, codominant marker development, linkage, and quantitative trait loci (QTL) mapping resources are limited in the important taxon. Accordingly, the objectives of this study were to develop simple sequence repeat (SSR) markers, construct a genetic map, and identify genomic regions associated with establishment rate. Five genomic SSR libraries were constructed, sequenced, and used in the development of 1003 validated SSR primer pairs (PPs). A linkage map was constructed using a first-generation selfed population derived from a genotype A12359 (2 = 4 = 36). A total of 249 polymorphic SSR PPs were mapped to 18 linkage groups (LGs). The total length of the map is 1094.7 cM, with an average marker interval of 4.3 cM. Ninety-eight out of 252 mapped loci (39%) were found to be distorted from the Mendelian 1:2:1 segregation ratio. Among the other 154 nondistorted loci, 88 coupling vs. 66 repulsion linkage phases were observed to confirm the allopolyploid origin of the parent. Ground coverage (GCR) phenotypic data in the establishment stage were collected in two replicated field trials. Quantitative trait loci mapping identified five genomic regions significantly related to the trait. The findings of this study provide valuable genetic tools and resources for genomic research, genetic improvement, and breeding new cultivars in the species.
普通狗牙根已广泛用作美国南部主要的暖季草坪、饲料和土壤稳定草。然而,在这个重要分类群中,共显性标记的开发、连锁和数量性状位点(QTL)作图资源有限。因此,本研究的目的是开发简单序列重复(SSR)标记、构建遗传图谱,并鉴定与建立率相关的基因组区域。构建了五个基因组 SSR 文库,进行了测序,并用于开发 1003 对验证 SSR 引物对(PPs)。利用基因型 A12359(2 = 4 = 36)的第一代自交群体构建了一个连锁图谱。总共将 249 个多态性 SSR PPs 映射到 18 个连锁群(LG)上。图谱的总长度为 1094.7cM,平均标记间隔为 4.3cM。252 个映射到的位点中有 98 个(39%)偏离了孟德尔 1:2:1 的分离比例。在其他 154 个非偏分离的位点中,观察到 88 个耦合与 66 个排斥连锁相,以确认亲本的异源多倍体起源。在建立阶段,在两个重复的田间试验中收集了地面覆盖率(GCR)表型数据。数量性状位点作图鉴定了与该性状显著相关的五个基因组区域。本研究的结果为该物种的基因组研究、遗传改良和培育新品种提供了有价值的遗传工具和资源。