Qiu Hongbo, Li Chunhong, Yang Wenzhu, Tan Kang, Yi Qiang, Yang Mei, Bai Guangxiao
College of Agriculture, Guizhou University, Guiyang, China.
Front Plant Sci. 2021 Sep 17;12:743869. doi: 10.3389/fpls.2021.743869. eCollection 2021.
Gray leaf spot (GLS), caused by different species of , is a fungal, non-soil-borne disease that causes serious reductions in maize yield worldwide. The identification of major quantitative trait loci (QTLs) for GLS resistance in maize is essential for developing marker-assisted selection strategies in maize breeding. Previous research found a significant difference ( < 0.01) in GLS resistance between T32 (highly resistant) and J51 (highly susceptible) genotypes of maize. Initial QTL analysis was conducted in an F population of 189 individuals utilizing genetic maps that were constructed using 181 simple sequence repeat (SSR) markers. One QTL () was detected, defined by the markers umc1130 and umc2354 in three environments. The QTL detected in the initial analysis was located in a 51.96-Mb genomic region of chromosome 8 and explained 7.89-14.71% of the phenotypic variation in GLS resistance in different environments. We also developed a near isogenic line (NIL) BCF population with 1,468 individuals and a BCF-Micro population with 180 individuals for fine mapping. High-resolution genetic and physical maps were constructed using six newly developed SSRs. The QTL- was narrowed down to a 124-kb region flanked by the markers ym20 and ym51 and explained up to 17.46% of the phenotypic variation in GLS resistance. The QTL- contained seven candidate genes, such as an and a ), and long intergenic non-coding RNAs (lincRNAs). The present study aimed to provide a foundation for the identification of candidate genes for GLS resistance in maize.
灰斑病（GLS）由不同种的[病原体名称缺失]引起，是一种真菌性非土传病害，在全球范围内导致玉米产量严重下降。鉴定玉米中抗灰斑病的主要数量性状位点（QTL）对于在玉米育种中制定标记辅助选择策略至关重要。先前的研究发现，玉米的T32（高抗）和J51（高感）基因型在灰斑病抗性上存在显著差异（P<0.01）。最初的QTL分析是在一个由189个个体组成的F群体中进行的，使用的是利用181个简单序列重复（SSR）标记构建的遗传图谱。在三个环境中检测到一个QTL（[QTL名称缺失]），由标记umc1130和umc2354定义。在初始分析中检测到的[QTL名称缺失]QTL位于8号染色体的一个51.96-Mb基因组区域，解释了不同环境中灰斑病抗性表型变异的7.89-14.71%。我们还开发了一个由1468个个体组成的近等基因系（NIL）BCF群体和一个由180个个体组成的BCF-Micro群体用于精细定位。使用六个新开发的SSR构建了高分辨率的遗传和物理图谱。[QTL名称缺失]QTL被缩小到一个由标记ym20和ym51侧翼的124-kb区域，解释了高达17.46%的灰斑病抗性表型变异。[QTL名称缺失]QTL包含七个候选基因，如一个[基因名称缺失]和一个[基因名称缺失]，以及长链基因间非编码RNA（lincRNA）。本研究旨在为鉴定玉米中抗灰斑病的候选基因提供基础。
