title: Independent genetic control of maize (Zea mays L.) kernel weight determination and its phenotypic plasticity.
abstract: Maize kernel weight (KW) is associated with the duration of the grain-filling period (GFD) and the rate of kernel biomass accumulation (KGR). It is also related to the dynamics of water and hence is physiologically linked to the maximum kernel water content (MWC), kernel desiccation rate (KDR), and moisture concentration at physiological maturity (MCPM). This work proposed that principles of phenotypic plasticity can help to consolidated the understanding of the environmental modulation and genetic control of these traits. For that purpose, a maize population of 245 recombinant inbred lines (RILs) was grown under different environmental conditions. Trait plasticity was calculated as the ratio of the variance of each RIL to the overall phenotypic variance of the population of RILs. This work found a hierarchy of plasticities: KDR ≈ GFD > MCPM > KGR > KW > MWC. There was no phenotypic and genetic correlation between traits per se and trait plasticities. MWC, the trait with the lowest plasticity, was the exception because common quantitative trait loci were found for the trait and its plasticity. Independent genetic control of a trait per se and genetic control of its plasticity is a condition for the independent evolution of traits and their plasticities. This allows breeders potentially to select for high or low plasticity in combination with high or low values of economically relevant traits.
authors.affiliation: Departamento de Producción Vegetal, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario, Campo Experimental Villarino S/N, S2125ZAA Zavalla, Prov. de Santa Fe, Argentina saprado@unr.edu.ar.
authors.forename: Santiago
authors.initials: S
authors.lastname: Alvarez Prado
authors.affiliation: South Australian Research and Development Institute, Waite Campus, Adelaide, SA 5001, Australia.
authors.forename: Víctor O
authors.initials: VO
authors.lastname: Sadras
authors.affiliation: Departamento de Producción Vegetal, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario, Campo Experimental Villarino S/N, S2125ZAA Zavalla, Prov. de Santa Fe, Argentina.
authors.forename: Lucas
authors.initials: L
authors.lastname: Borrás
mesh_terms: D004777:Environment; D010641:Phenotype; D040641:Quantitative Trait Loci; D019655:Quantitative Trait, Heritable; D012639:Seeds / Q000254:growth & development*; D003313:Zea mays / Q000502:physiology*
keywords: Grain-filling duration; kernel desiccation rate; kernel growth rate; kernel weight; maximum kernel water content; moisture concentration at physiological maturity; phenotypic plasticity; quantitative trait loci.