Hao Derong, Xue Lin, Zhang Zhenliang, Cheng Yujing, Chen Guoqing, Zhou Guangfei, Li Pengcheng, Yang Zefeng, Xu Chenwu
Jiangsu Key Laboratory of Crop Genetics and Physiology, Co-Innovation Center for Modern Production Technology of Grain Crops, Key Laboratory of Plant Functional Genomics of the Ministry of Education, Yangzhou University, Yangzhou 225009, China.
Nantong Key Laboratory for Exploitation of Crop Genetic Resources and Molecular Breeding, Jiangsu Yanjiang Institute of Agricultural Sciences, Nantong 226541, China.
Breed Sci. 2019 Sep;69(3):420-428. doi: 10.1270/jsbbs.18185. Epub 2019 Jun 27.
Yield improvement is a top priority for maize breeding. Kernel size and weight are important determinants of maize grain yield. In this study, a recombinant inbred line (RIL) population and an association panel were used to identify quantitative trait loci (QTLs) for four maize kernel-related traits: kernel length, width, thickness and 100-kernel weight. Twenty-seven QTLs were identified for kernel-related traits across three environments and the best linear unbiased predictions (BLUPs) of each trait by linkage analysis, and four QTLs were stably detected in more than two environments. Additionally, 29 single nucleotide polymorphisms (SNPs) were identified as significantly associated with the four kernel-related traits and BLUPs by genome-wide association study, and two loci could be stably detected in both environments. In total, four QTLs/SNPs were co-associated with various traits in both populations. Using combined-linkage analysis and association mapping, PZE-101066560 on chromosome 1, associated with kernel width and with 100-kernel weight in the association panel, was co-localized within the QTL interval of for kernel width in the RILs. Two annotated genes in the candidate region were considered as potential candidate genes. The QTLs and candidate genes identified here will facilitate molecular breeding for grain yield improvement in maize.
提高产量是玉米育种的首要任务。籽粒大小和重量是玉米产量的重要决定因素。在本研究中，利用重组自交系（RIL）群体和关联群体鉴定了与玉米籽粒相关的四个性状的数量性状位点（QTL）：籽粒长度、宽度、厚度和百粒重。通过连锁分析在三个环境中鉴定出27个与籽粒相关性状的QTL以及每个性状的最佳线性无偏预测值（BLUP），并且在两个以上环境中稳定检测到4个QTL。此外，通过全基因组关联研究鉴定出29个单核苷酸多态性（SNP）与四个籽粒相关性状和BLUP显著相关，并且在两个环境中都能稳定检测到两个位点。总共，在两个群体中有4个QTL/SNP与各种性状共同关联。利用连锁分析和关联作图相结合的方法，在第1染色体上与籽粒宽度相关且在关联群体中与百粒重相关的PZE-101066560，与RIL群体中籽粒宽度的QTL区间共定位。候选区域中的两个注释基因被认为是潜在的候选基因。这里鉴定出的QTL和候选基因将有助于玉米籽粒产量提高的分子育种。
