National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, China.
Wuhan Genoseq Technology Co., Ltd, Wuhan, 430070, China.
Theor Appl Genet. 2020 Aug;133(8):2521-2533. doi: 10.1007/s00122-020-03614-z. Epub 2020 May 28.
The genetic basis of GLS resistance was dissected using two DH populations sharing a common resistant parent. A major QTL repeatedly detected in multiple developmental stages and environments was fine mapped in a backcross population. Grey leaf spot (GLS), caused by Cercospora zeae-maydis or Cercospora zeina, is a highly destructive foliar disease worldwide. However, the mechanism of resistance against GLS is not well understood. To study the inheritance of this resistance, we developed two doubled haploid (DH) populations sharing a common resistant parent. The two DH populations were grown in two locations representing the typical maize-growing mountain area in Southwest China for 2 years. GLS disease severity was investigated 2 or 3 times until maturity in the 2 years, and the area under the disease progress curve was calculated. Two high-density linkage maps were constructed by genotyping-by-sequencing. A total of 22 quantitative trait loci (QTLs) were detected for GLS resistance, with most QTLs being repeatedly detected in different stages, locations and years. The confidence intervals of two major QTLs (qGLS_Y2-2 and qGLS_Z2-1) on chromosome 2 from the two DH populations overlapped with each other and were integrated into one consensus QTL (qGLS_YZ2-1). Using highly resistant and highly susceptible plants from a BC population, we fine mapped this genetic locus to a genomic region of 2.4 Mb. Using a panel of 255 inbred lines from breeding programmes, we detected associations between markers in the qGLS_YZ2-1 region and GLS resistance. The peak marker (ID-B1) will be very useful for marker-assisted breeding for GLS resistance.
利用两个共享共同抗性亲本的双单倍体 (DH) 群体，剖析了 GLS 抗性的遗传基础。在回交群体中，对在多个发育阶段和环境中反复检测到的一个主要 QTL 进行了精细定位。由玉米叶斑病菌 (Cercospora zeae-maydis 或 Cercospora zeina) 引起的灰斑病 (GLS) 是全球范围内一种极具破坏性的叶部病害。然而，对 GLS 抗性的机制尚不完全清楚。为了研究这种抗性的遗传，我们开发了两个共享共同抗性亲本的双单倍体 (DH) 群体。这两个 DH 群体在代表中国西南典型玉米种植区的两个地点种植了两年。在这两年中，在成熟之前进行了 2 或 3 次 GLS 疾病严重程度调查，并计算了疾病进展曲线下的面积。通过测序基因分型构建了两个高密度连锁图谱。共检测到 22 个 GLS 抗性数量性状位点 (QTL)，其中大多数 QTL 在不同阶段、地点和年份都被反复检测到。两个 DH 群体在第 2 号染色体上的两个主要 QTL（qGLS_Y2-2 和 qGLS_Z2-1）的置信区间相互重叠，并整合为一个共识 QTL（qGLS_YZ2-1）。利用来自 BC 群体的高抗和高感植株，我们将该遗传位点精细定位到 2.4 Mb 的基因组区域。使用来自育种计划的 255 个自交系的一个小组，我们检测到 qGLS_YZ2-1 区域内标记与 GLS 抗性之间的关联。峰标记 (ID-B1) 将非常有助于 GLS 抗性的标记辅助选择育种。
