title: Analysis of recombination QTLs, segregation distortion, and epistasis for fitness in maize multiple populations using ultra-high-density markers.
abstract: Using two nested association mapping populations and high-density markers, some important genomic regions controlling recombination frequency and segregation distortion were detected. Understanding the maize genomic features would be useful for the study of genetic diversity and evolution and for maize breeding. Here, we used two maize nested association mapping (NAM) populations separately derived in China (CN-NAM) and the US (US-NAM) to explore the maize genomic features. The two populations containing 36 families and about 7000 recombinant inbred lines were evaluated with genotyping-by-sequencing. Through the comparison between the two NAMs, we revealed that segregation distortion is little, whereas epistasis for fitness is present in the two maize NAM populations. When conducting quantitative trait loci (QTL) mapping for the total number of recombination events, we detected 14 QTLs controlling recombination. Using high-density markers to identify segregation distortion regions (SDRs), a total of 445 SDRs were detected within the 36 families, among which 15 common SDRs were found in at least ten families. About 80 % of the known maize gametophytic factors (ga) genes controlling segregation distortion were overlapped with highly significant SDRs. In addition, we also found that the regions with high recombination rate and high gene density usually tended to have little segregation distortion. This study will facilitate population genetic studies and gene cloning affecting recombination variation and segregation distortion in maize, which can improve plant breeding progress.
authors.affiliation: Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors.forename: Chunhui
authors.initials: C
authors.lastname: Li
authors.affiliation: Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors.forename: Yongxiang
authors.initials: Y
authors.lastname: Li
authors.affiliation: Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors.forename: Yunsu
authors.initials: Y
authors.lastname: Shi
authors.affiliation: Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors.forename: Yanchun
authors.initials: Y
authors.lastname: Song
authors.affiliation: Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
authors.forename: Dengfeng
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Institute for Genomic Diversity, Cornell University, Ithaca, NY, USA.
authors.forename: Edward S
authors.initials: ES
authors.lastname: Buckler
authors.affiliation: Institute for Genomic Diversity, Cornell University, Ithaca, NY, USA.
authors.forename: Zhiwu
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China. liyu03@caas.cn.
authors.forename: Yu
authors.initials: Y
authors.lastname: Li
authors.affiliation: Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, 100081, China. wangtianyu@263.net.
authors.forename: Tianyu
authors.initials: T
authors.lastname: Wang
mesh_terms: D002874:Chromosome Mapping; D004843:Epistasis, Genetic; D056084:Genetic Fitness; D005819:Genetic Markers; D014644:Genetic Variation; D018745:Genome, Plant; D005838:Genotype; D060005:Genotyping Techniques; D040641:Quantitative Trait Loci; D011995:Recombination, Genetic; D003313:Zea mays / Q000235:genetics*
chemical_list: D005819:Genetic Markers