title: QTLs for seed vigor-related traits identified in maize seeds germinated under artificial aging conditions.
abstract: High seed vigor is important for agricultural production due to the associated potential for increased growth and productivity. However, a better understanding of the underlying molecular mechanisms is required because the genetic basis for seed vigor remains unknown. We used single-nucleotide polymorphism (SNP) markers to map quantitative trait loci (QTLs) for four seed vigor traits in two connected recombinant inbred line (RIL) maize populations under four treatment conditions during seed germination. Sixty-five QTLs distributed between the two populations were identified and a meta-analysis was used to integrate genetic maps. Sixty-one initially identified QTLs were integrated into 18 meta-QTLs (mQTLs). Initial QTLs with contribution to phenotypic variation values of R(2)>10% were integrated into mQTLs. Twenty-three candidate genes for association with seed vigor traits coincided with 13 mQTLs. The candidate genes had functions in the glycolytic pathway and in protein metabolism. QTLs with major effects (R(2)>10%) were identified under at least one treatment condition for mQTL2, mQTL3-2, and mQTL3-4. Candidate genes included a calcium-dependent protein kinase gene (302810918) involved in signal transduction that mapped in the mQTL3-2 interval associated with germination energy (GE) and germination percentage (GP), and an hsp20/alpha crystallin family protein gene (At5g51440) that mapped in the mQTL3-4 interval associated with GE and GP. Two initial QTLs with a major effect under at least two treatment conditions were identified for mQTL5-2. A cucumisin-like Ser protease gene (At5g67360) mapped in the mQTL5-2 interval associated with GP. The chromosome regions for mQTL2, mQTL3-2, mQTL3-4, and mQTL5-2 may be hot spots for QTLs related to seed vigor traits. The mQTLs and candidate genes identified in this study provide valuable information for the identification of additional quantitative trait genes.
authors.affiliation: College of Agronomy, Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, China; College of Agronomy, Henan University of Science and Technology, Luoyang, China.
authors.forename: Zanping
authors.initials: Z
authors.lastname: Han
authors.affiliation: College of Agronomy, Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, China.
authors.forename: Lixia
authors.initials: L
authors.lastname: Ku
authors.affiliation: College of Agronomy, Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, China.
authors.forename: Zhenzhen
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: College of Agronomy, Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.affiliation: College of Agronomy, Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, China.
authors.forename: Shulei
authors.initials: S
authors.lastname: Guo
authors.affiliation: College of Agronomy, Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, China.
authors.forename: Haiying
authors.initials: H
authors.lastname: Liu
authors.affiliation: College of Agronomy, Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, China.
authors.forename: Ruifang
authors.initials: R
authors.lastname: Zhao
authors.affiliation: College of Agronomy, Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, China.
authors.forename: Zhenzhen
authors.initials: Z
authors.lastname: Ren
authors.affiliation: College of Agronomy, Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, China.
authors.forename: Liangkun
authors.initials: L
authors.lastname: Zhang
authors.affiliation: College of Agronomy, Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, China.
authors.forename: Huihui
authors.initials: H
authors.lastname: Su
authors.affiliation: College of Agronomy, Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Dong
authors.affiliation: College of Agronomy, Synergetic Innovation Center of Henan Grain Crops and National Key Laboratory of wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou, China.
authors.forename: Yanhui
authors.initials: Y
authors.lastname: Chen
mesh_terms: D000375:Aging / Q000235:genetics; D002874:Chromosome Mapping; D032461:Chromosomes, Plant; D008040:Genetic Linkage; D005819:Genetic Markers; D018525:Germination / Q000235:genetics*; D006823:Hybrid Vigor / Q000235:genetics*; D007178:Inbreeding; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci; D019655:Quantitative Trait, Heritable; D012639:Seeds / Q000235:genetics*; D003313:Zea mays / Q000235:genetics*
chemical_list: D005819:Genetic Markers