PHENOTYPIC PLASTICITY OF BIOMASS PRODUCTION AND ITS PARTITIONING: DIFFERENCES BETWEEN INBREEDS AND HYBRIDS

GALIZIA, L.A.; D'ANDREA, K.E.; CIRILO, A.G.; OTEGUI, MARIA E.

Pergamino

Congreso; XI Congreso Nacional del Maíz; 2018

AIANBA

Maize grain yield (GY) is determined by genotype (G), environment (E) and G × E interaction effects that act through the expression of three main physiological traits around flowering: plant (PGRCP) and ear growth rates (EGRCP), and biomass partitioning to the ears. Additionally, inbreeds (I) and hybrids (H) may differ in their responses to changes in environmental conditions. The objectives of this work are (i) to compare the phenotypic plasticity of I and H for GY, biomass production, biomass partitioning and other related ecophysiological traits, and (ii) to study the expression of absolute heterosis (Habs) variations across a balanced environmental index (EIB) built from 14 contrasting environments. A 6-inbred, complete diallel mating design was used. Phenotypic plasticity was different for I and H in all traits except harvest index and apical ear reproductive efficiency. For these traits, we detected no trend in the heterosis response to the EIB. For traits related with biomass accumulation, H had higher mean values and plasticity than I. Instead, I showed higher mean values and plasticity for prolificacy and EGRCP/PGRCP.