Wu Jizhong, Qiao Linyi, Liu Ying, Fu Bisheng, Nagarajan Ragupathi, Rauf Yahya, Jia Haiyan, Yan Liuling
Institute of Germplasm Resources and Biotechnology, Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu, China.
Department of Plant and Soil Sciences, Oklahoma State University, Stillwater, OK, United States.
Front Plant Sci. 2022 Aug 26;13:992811. doi: 10.3389/fpls.2022.992811. eCollection 2022.
Molecular markers are developed to accelerate deployment of genes for desirable traits segregated in a bi-parental population of recombinant inbred lines (RILs) or doubled haplotype (DH) lines for mapping. However, it would be the most effective if such markers for multiple traits could be identified in an F population. In this study, single nucleotide polymorphisms (SNP) chips were used to identify major genes for heading date and awn in an F population without developing RILs or DH lines. The population was generated from a cross between a locally adapted spring wheat cultivar "Ningmaizi119" and a winter wheat cultivar "Tabasco" with a diverse genetic background. It was found that the dominant allele could make Ningmaizi119 flowered a few months earlier than Tabasco in the greenhouse and without vernalization. The observed effects of the allele were validated in F populations. It was also found that the dominant allele for awnless trait in Tabasco or the recessive allele for awn trait in Ningmaizi119 was segregated in the F population. The allelic variation in the gene relies not only on the DNA polymorphisms in the promoter but also on gene copy number, with one copy in Ningmaizi119 but two copies in Tabasco based on RT-PCR results. According to wheat genome sequences, cultivar "Mattis" has two copies and cultivar "Spelta" has four copies in a chromosome that was uncharacterized (ChrUN), in addition to one copy on chromosome 5A. This study rapidly characterized the effects of the dominant allele and identified the haplotype of in gene copy number in the F segregation population of common wheat will accelerate their deployment in cycling lines in breeding.
开发分子标记是为了加速将具有理想性状的基因应用于重组自交系（RIL）或双单倍体（DH）系的双亲群体中进行定位。然而，如果能在F群体中鉴定出控制多个性状的此类标记，那将是最有效的。在本研究中，利用单核苷酸多态性（SNP）芯片在未构建RIL或DH系的F群体中鉴定抽穗期和芒的主效基因。该群体由当地适应性强的春小麦品种“宁麦籽119”与遗传背景多样的冬小麦品种“塔巴斯科”杂交产生。研究发现，在温室中且未经春化处理时，显性等位基因可使宁麦籽119比塔巴斯科提前几个月开花。该等位基因的观察效应在F群体中得到了验证。还发现，塔巴斯科中无芒性状的显性等位基因或宁麦籽119中芒性状的隐性等位基因在F群体中发生了分离。根据逆转录聚合酶链反应（RT-PCR）结果，该基因的等位变异不仅依赖于启动子中的DNA多态性，还依赖于基因拷贝数，宁麦籽119中有一个拷贝，而塔巴斯科中有两个拷贝。根据小麦基因组序列，除了5A染色体上有一个拷贝外，品种“马蒂斯”在一条未鉴定的染色体（ChrUN）上有两个拷贝，品种“斯佩尔特小麦”有四个拷贝。本研究快速表征了显性等位基因的效应，并鉴定了普通小麦F分离群体中该基因拷贝数的单倍型，这将加速其在育种轮回系中的应用。
