title: A genetic relationship between nitrogen use efficiency and seedling root traits in maize as revealed by QTL analysis.
abstract: That root system architecture (RSA) has an essential role in nitrogen acquisition is expected in maize, but the genetic relationship between RSA and nitrogen use efficiency (NUE) traits remains to be elucidated. Here, the genetic basis of RSA and NUE traits was investigated in maize using a recombination inbred line population that was derived from two lines contrasted for both traits. Under high-nitrogen and low-nitrogen conditions, 10 NUE- and 9 RSA-related traits were evaluated in four field environments and three hydroponic experiments, respectively. In contrast to nitrogen utilization efficiency (NutE), nitrogen uptake efficiency (NupE) had significant phenotypic correlations with RSA, particularly the traits of seminal roots (r = 0.15-0.31) and crown roots (r = 0.15-0.18). A total of 331 quantitative trait loci (QTLs) were detected, including 184 and 147 QTLs for NUE- and RSA-related traits, respectively. These QTLs were assigned into 64 distinct QTL clusters, and ~70% of QTLs for nitrogen-efficiency (NUE, NupE, and NutE) coincided in clusters with those for RSA. Five important QTLs clusters at the chromosomal regions bin1.04, 2.04, 3.04, 3.05/3.06, and 6.07/6.08 were found in which QTLs for both traits had favourable effects from alleles coming from the large-rooted and high-NupE parent. Introgression of these QTL clusters in the advanced backcross-derived lines conferred mean increases in grain yield of ~14.8% for the line per se and ~15.9% in the testcross. These results reveal a significant genetic relationship between RSA and NUE traits, and uncover the most promising genomic regions for marker-assisted selection of RSA to improve NUE in maize.
authors: Key Laboratory of Plant-Soil Interaction, MOE, Center for Resources, Environment and Food Security, College Resources and Environmental Sciences, China Agricultural University, Beijing, China 100193.
authors: Pengcheng
authors: P
authors: Li
authors: Key Laboratory of Plant-Soil Interaction, MOE, Center for Resources, Environment and Food Security, College Resources and Environmental Sciences, China Agricultural University, Beijing, China 100193 yuanlixing@cau.edu.cn caucfj@cau.edu.cn.
authors: Fanjun
authors: F
authors: Chen
authors: Key Laboratory of Plant-Soil Interaction, MOE, Center for Resources, Environment and Food Security, College Resources and Environmental Sciences, China Agricultural University, Beijing, China 100193.
authors: Hongguang
authors: H
authors: Cai
authors: Key Laboratory of Plant-Soil Interaction, MOE, Center for Resources, Environment and Food Security, College Resources and Environmental Sciences, China Agricultural University, Beijing, China 100193.
authors: Jianchao
authors: J
authors: Liu
authors: Key Laboratory of Plant-Soil Interaction, MOE, Center for Resources, Environment and Food Security, College Resources and Environmental Sciences, China Agricultural University, Beijing, China 100193.
authors: Qingchun
authors: Q
authors: Pan
authors: Key Laboratory of Plant-Soil Interaction, MOE, Center for Resources, Environment and Food Security, College Resources and Environmental Sciences, China Agricultural University, Beijing, China 100193.
authors: Zhigang
authors: Z
authors: Liu
authors: Key Laboratory of Plant-Soil Interaction, MOE, Center for Resources, Environment and Food Security, College Resources and Environmental Sciences, China Agricultural University, Beijing, China 100193.
authors: Riliang
authors: R
authors: Gu
authors: Key Laboratory of Plant-Soil Interaction, MOE, Center for Resources, Environment and Food Security, College Resources and Environmental Sciences, China Agricultural University, Beijing, China 100193.
authors: Guohua
authors: G
authors: Mi
authors: Key Laboratory of Plant-Soil Interaction, MOE, Center for Resources, Environment and Food Security, College Resources and Environmental Sciences, China Agricultural University, Beijing, China 100193.
authors: Fusuo
authors: F
authors: Zhang
authors: Key Laboratory of Plant-Soil Interaction, MOE, Center for Resources, Environment and Food Security, College Resources and Environmental Sciences, China Agricultural University, Beijing, China 100193 yuanlixing@cau.edu.cn caucfj@cau.edu.cn.
authors: Lixing
authors: L
authors: Yuan
mesh_terms: D000483:Alleles; D016000:Cluster Analysis; D002523:Edible Grain / Q000235:genetics / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism*; D010641:Phenotype; D018517:Plant Roots / Q000235:genetics* / Q000378:metabolism; D040641:Quantitative Trait Loci / Q000235:genetics*; D036226:Seedlings / Q000235:genetics / Q000378:metabolism; D003313:Zea mays / Q000235:genetics* / Q000378:metabolism
chemical_list: D009584:Nitrogen
keywords: Genetic relationship; QTL analysis; QTL clusters; Zea mays L.; nitrogen uptake efficiency; nitrogen use efficiency; root system architecture; roots