Departamento de Producción Vegetal, Facultad de Ciencias Agrarias, Universidad Nacional de Rosario, Campo Experimental Villarino S/N, S2125ZAA Zavalla, Prov. de Santa Fe, Argentina
South Australian Research and Development Institute, Waite Campus, Adelaide, SA 5001, Australia.
J Exp Bot. 2014 Aug;65(15):4479-87. doi: 10.1093/jxb/eru215. Epub 2014 Jun 2.
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.
玉米籽粒重量（KW）与灌浆期持续时间（GFD）和籽粒生物量积累率（KGR）有关。它还与水分动态有关，因此在生理上与最大籽粒含水量（MWC）、籽粒干燥速率（KDR）和生理成熟时的水分浓度（MCPM）有关。本研究提出，表型可塑性原则有助于整合对这些性状的环境调节和遗传控制的理解。为此，在不同环境条件下种植了 245 个重组自交系（RIL）的玉米群体。性状可塑性的计算方法是每个 RIL 的方差与 RIL 群体的整体表型方差的比值。本研究发现了一个可塑性层次结构：KDR≈GFD>MCPM>KGR>KW>MWC。性状本身与其可塑性之间没有表型和遗传相关性。MWC 是可塑性最低的性状，但它是个例外，因为该性状及其可塑性存在共同的数量性状基因座。性状本身的独立遗传控制和其可塑性的遗传控制是性状及其可塑性独立进化的条件。这使得育种者有可能在选择具有经济价值的高或低的性状值的同时，选择高或低的可塑性。
