Factors affecting the genotype × environment interaction in spring triticale grown in a Mediterranean environment

The identification of the genotypic and environmental factors responsible for the genotype by environment interaction is essential in any breeding program. A Multi Environmental Trial (MET) including 3 years, 3 locations and 14 lines of spring triticale (× TriticosecaleWittmack) was carried out in a Mediterranean environment (Sardinia, Italy). Water available to the crops was calculated through a model run with the environmental variables and the phenological data recorded in each environment. Yield, yield components and heading date were used to perform an Additive Main effects and Multiplicative Interaction (AMMI) analysis. Interaction for yield was relevant only in 2 environments out of 8, one characterised by a late sowing, the other by the warmest pre-anthesis period. Correlations between Interaction Principal Component Axis (IPCA) scores and environmental and genotypic variables showed that genotype by environment interaction for yield and kernels per m2 is related to interaction for phenology but not to the yield level. Yield level was significantly correlated with the water availability. Genotype by environment interaction for yield is mainly determined by thermal conditions in the pre-anthesis period, genotypic photoperiodic sensitivity and sowing time.