title: Genetic variation of growth dynamics in maize (Zea mays L.) revealed through automated non-invasive phenotyping.
abstract: Hitherto, most quantitative trait loci of maize growth and biomass yield have been identified for a single time point, usually the final harvest stage. Through this approach cumulative effects are detected, without considering genetic factors causing phase-specific differences in growth rates. To assess the genetics of growth dynamics, we employed automated non-invasive phenotyping to monitor the plant sizes of 252 diverse maize inbred lines at 11 different developmental time points; 50 k SNP array genotype data were used for genome-wide association mapping and genomic selection. The heritability of biomass was estimated to be over 71%, and the average prediction accuracy amounted to 0.39. Using the individual time point data, 12 main effect marker-trait associations (MTAs) and six pairs of epistatic interactions were detected that displayed different patterns of expression at various developmental time points. A subset of them also showed significant effects on relative growth rates in different intervals. The detected MTAs jointly explained up to 12% of the total phenotypic variation, decreasing with developmental progression. Using non-parametric functional mapping and multivariate mapping approaches, four additional marker loci affecting growth dynamics were detected. Our results demonstrate that plant biomass accumulation is a complex trait governed by many small effect loci, most of which act at certain restricted developmental phases. This highlights the need for investigation of stage-specific growth affecting genes to elucidate important processes operating at different developmental phases.
authors.affiliation: Department of Molecular Genetics, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstraße 3, D-06466, Seeland, Germany.|Department of Plant Sciences, Chuka University, P.O. Box 109 - 60400, Chuka, Kenya.
authors.forename: Moses M
authors.initials: MM
authors.lastname: Muraya
authors.affiliation: Department of Breeding Research, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstraße 3, D-06466, Seeland, Germany.
authors.forename: Jianting
authors.initials: J
authors.lastname: Chu
authors.affiliation: Department of Breeding Research, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstraße 3, D-06466, Seeland, Germany.
authors.forename: Yusheng
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Molecular Genetics, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstraße 3, D-06466, Seeland, Germany.
authors.forename: Astrid
authors.initials: A
authors.lastname: Junker
authors.affiliation: Department of Molecular Genetics, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstraße 3, D-06466, Seeland, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Klukas
authors.affiliation: Department of Breeding Research, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstraße 3, D-06466, Seeland, Germany.
authors.forename: Jochen C
authors.initials: JC
authors.lastname: Reif
authors.affiliation: Department of Molecular Genetics, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstraße 3, D-06466, Seeland, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Altmann
mesh_terms: D004843:Epistasis, Genetic; D005819:Genetic Markers; D014644:Genetic Variation; D055106:Genome-Wide Association Study; D057166:High-Throughput Screening Assays / Q000379:methods; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci; D003313:Zea mays / Q000235:genetics* / Q000254:growth & development*
chemical_list: D005819:Genetic Markers
keywords: automated non-invasive phenotyping; biomass accumulation and production; epistasis; genome-wide association study; genome-wide selection; growth dynamics