title: QTL analysis of Kernel-related traits in maize using an immortalized F2 population.
abstract: Kernel size and weight are important determinants of grain yield in maize. In this study, multivariate conditional and unconditional quantitative trait loci (QTL), and digenic epistatic analyses were utilized in order to elucidate the genetic basis for these kernel-related traits. Five kernel-related traits, including kernel weight (KW), volume (KV), length (KL), thickness (KT), and width (KWI), were collected from an immortalized F2 (IF2) maize population comprising of 243 crosses performed at two separate locations over a span of two years. A total of 54 unconditional main QTL for these five kernel-related traits were identified, many of which were clustered in chromosomal bins 6.04-6.06, 7.02-7.03, and 10.06-10.07. In addition, qKL3, qKWI6, qKV10a, qKV10b, qKW10a, and qKW7a were detected across multiple environments. Sixteen main QTL were identified for KW conditioned on the other four kernel traits (KL, KWI, KT, and KV). Thirteen main QTL were identified for KV conditioned on three kernel-shape traits. Conditional mapping analysis revealed that KWI and KV had the strongest influence on KW at the individual QTL level, followed by KT, and then KL; KV was mostly strongly influenced by KT, followed by KWI, and was least impacted by KL. Digenic epistatic analysis identified 18 digenic interactions involving 34 loci over the entire genome. However, only a small proportion of them were identical to the main QTL we detected. Additionally, conditional digenic epistatic analysis revealed that the digenic epistasis for KW and KV were entirely determined by their constituent traits. The main QTL identified in this study for determining kernel-related traits with high broad-sense heritability may play important roles during kernel development. Furthermore, digenic interactions were shown to exert relatively large effects on KL (the highest AA and DD effects were 4.6% and 6.7%, respectively) and KT (the highest AA effects were 4.3%).
authors.affiliation: College of Agronomy/Key Laboratory of Physiological Ecology and Genetic Improvement of Food Crops in Henan Province, Henan Agricultural University, Zhengzhou, China.
authors.forename: Zhanhui
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: College of Agronomy/Key Laboratory of Physiological Ecology and Genetic Improvement of Food Crops in Henan Province, Henan Agricultural University, Zhengzhou, China.
authors.forename: Zonghua
authors.initials: Z
authors.lastname: Liu
authors.affiliation: College of Agronomy/Key Laboratory of Physiological Ecology and Genetic Improvement of Food Crops in Henan Province, Henan Agricultural University, Zhengzhou, China.
authors.forename: Yanmin
authors.initials: Y
authors.lastname: Hu
authors.affiliation: College of Agronomy/Key Laboratory of Physiological Ecology and Genetic Improvement of Food Crops in Henan Province, Henan Agricultural University, Zhengzhou, China.
authors.forename: Weihua
authors.initials: W
authors.lastname: Li
authors.affiliation: College of Agronomy/Key Laboratory of Physiological Ecology and Genetic Improvement of Food Crops in Henan Province, Henan Agricultural University, Zhengzhou, China.
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Fu
authors.affiliation: College of Agronomy/Key Laboratory of Physiological Ecology and Genetic Improvement of Food Crops in Henan Province, Henan Agricultural University, Zhengzhou, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Ding
authors.affiliation: College of Agronomy/Key Laboratory of Physiological Ecology and Genetic Improvement of Food Crops in Henan Province, Henan Agricultural University, Zhengzhou, China.
authors.forename: Haochuan
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Biological Sciences, Michigan Technological University, Houghton, Michigan, United States of America.
authors.forename: Mengmeng
authors.initials: M
authors.lastname: Qiao
authors.affiliation: College of Agronomy/Key Laboratory of Physiological Ecology and Genetic Improvement of Food Crops in Henan Province, Henan Agricultural University, Zhengzhou, China.
authors.forename: Jihua
authors.initials: J
authors.lastname: Tang
mesh_terms: D032461:Chromosomes, Plant; D003433:Crosses, Genetic; D004843:Epistasis, Genetic / Q000235:genetics*; D040641:Quantitative Trait Loci / Q000235:genetics; D003313:Zea mays / Q000235:genetics*