title: Genetic dissection of maize seedling root system architecture traits using an ultra-high density bin-map and a recombinant inbred line population.
abstract: Maize (Zea mays) root system architecture (RSA) mediates the key functions of plant anchorage and acquisition of nutrients and water. In this study, a set of 204 recombinant inbred lines (RILs) was derived from the widely adapted Chinese hybrid ZD958(Zheng58 × Chang7-2), genotyped by sequencing (GBS) and evaluated as seedlings for 24 RSA related traits divided into primary, seminal and total root classes. Significant differences between the means of the parental phenotypes were detected for 18 traits, and extensive transgressive segregation in the RIL population was observed for all traits. Moderate to strong relationships among the traits were discovered. A total of 62 quantitative trait loci (QTL) were identified that individually explained from 1.6% to 11.6% (total root dry weight/total seedling shoot dry weight) of the phenotypic variation. Eighteen, 24 and 20 QTL were identified for primary, seminal and total root classes of traits, respectively. We found hotspots of 5, 3, 4 and 12 QTL in maize chromosome bins 2.06, 3.02-03, 9.02-04, and 9.05-06, respectively, implicating the presence of root gene clusters or pleiotropic effects. These results characterized the phenotypic variation and genetic architecture of seedling RSA in a population derived from a successful maize hybrid.
authors.affiliation: State Key Laboratory of Agrobiotechnology and National Maize Improvement Center of China, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
authors.forename: Weibin
authors.initials: W
authors.lastname: Song
authors.affiliation: State Key Laboratory of Agrobiotechnology and National Maize Improvement Center of China, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
authors.forename: Baobao
authors.initials: B
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Agrobiotechnology and National Maize Improvement Center of China, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Hauck
authors.affiliation: State Key Laboratory of Agrobiotechnology and National Maize Improvement Center of China, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Dong
authors.affiliation: State Key Laboratory of Agrobiotechnology and National Maize Improvement Center of China, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
authors.forename: Jieping
authors.initials: J
authors.lastname: Li
authors.affiliation: State Key Laboratory of Agrobiotechnology and National Maize Improvement Center of China, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
authors.forename: Jinsheng
authors.initials: J
authors.lastname: Lai
mesh_terms: D005819:Genetic Markers; D018527:Hydroponics; D007178:Inbreeding; D010641:Phenotype; D000069600:Plant Breeding; D018517:Plant Roots / Q000033:anatomy & histology* / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D040641:Quantitative Trait Loci / Q000235:genetics; D019655:Quantitative Trait, Heritable; D011995:Recombination, Genetic / Q000235:genetics*; D036226:Seedlings / Q000235:genetics* / Q000254:growth & development; D003313:Zea mays / Q000235:genetics*
chemical_list: D005819:Genetic Markers
keywords: Maize; QTL; bin map; genotyping by sequencing (GBS); root system architecture