Genetic dissection of N use efficiency using maize inbred lines and testcrosses
Xiaoyang Liu,
Kunhui He,
Farhan Ali,
Dongdong Li,
Hongguang Cai,
Hongwei Zhang,
Lixing Yuan,
Wenxin Liu,
Guohua Mi,
Fanjun Chen,
Qingchun Pan
Affiliations
Xiaoyang Liu
Key Laboratory of Plant-Soil Interactions of Ministry of Education, National Academy of Agriculture Green Development, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
Kunhui He
Key Laboratory of Plant-Soil Interactions of Ministry of Education, National Academy of Agriculture Green Development, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
Farhan Ali
Cereal Crops Research Institute, Pirsabak Nowshera, Pakistan
Dongdong Li
College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
Hongguang Cai
Institute of Agricultural Resources and Environment, Jilin Academy of Agricultural Sciences, Changchun 130033, Jilin, China
Hongwei Zhang
Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China
Lixing Yuan
Key Laboratory of Plant-Soil Interactions of Ministry of Education, National Academy of Agriculture Green Development, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
Wenxin Liu
College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
Guohua Mi
Key Laboratory of Plant-Soil Interactions of Ministry of Education, National Academy of Agriculture Green Development, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
Fanjun Chen
Key Laboratory of Plant-Soil Interactions of Ministry of Education, National Academy of Agriculture Green Development, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; Sanya Institute, China Agricultural University, Sanya 572025, Hainan, China
Qingchun Pan
Key Laboratory of Plant-Soil Interactions of Ministry of Education, National Academy of Agriculture Green Development, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; Sanya Institute, China Agricultural University, Sanya 572025, Hainan, China; Corresponding author.
Although the use of heterosis in maize breeding has increased crop productivity, the genetic causes underlying heterosis for nitrogen (N) use efficiency (NUE) have been insufficiently investigated. In this study, five N-response traits and five low-N-tolerance traits were investigated using two inbred line populations (ILs) consisting of recombinant inbred lines (RIL) and advanced backcross (ABL) populations, derived from crossing Ye478 with Wu312. Both populations were crossed with P178 to construct two testcross populations. IL populations, their testcross populations, and the midparent heterosis (MPH) for NUE were investigated. Kernel weight, kernel number, and kernel number per row were sensitive to N level and ILs showed higher N response than did the testcross populations. Based on a high-density linkage map, 138 quantitative trait loci (QTL) were mapped, each explaining 5.6%–38.8% of genetic variation. There were 52, 34 and 52 QTL for IL populations, MPH, and testcross populations, respectively. The finding that 7.6% of QTL were common to the ILs and their testcross populations and that 11.7% were common to the MPH and testcross population indicated that heterosis for NUE traits was regulated by non-additive and non-dominant loci. A QTL on chromosome 5 explained 27% of genetic variation in all of the traits and Gln1-3 was identified as a candidate gene for this QTL. Genome-wide prediction of NUE traits in the testcross populations showed 14%–51% accuracy. Our results may be useful for clarifying the genetic basis of heterosis for NUE traits and the candidate gene may be used for genetic improvement of maize NUE.
