Genetic basis of phenotypic plasticity and genotype x environment
interaction in a multi-parental population
Deciphering the genetic basis of phenotypic plasticity and genotype x
environment interaction (GxE) is of primary importance for plant
breeding in the context of global climate change. Tomato is a widely
cultivated crop that can grow in different geographical habitats and
which evinces a great capacity of expressing phenotypic plasticity. We
used a multi-parental advanced generation intercross (MAGIC) tomato
population to explore GxE and plasticity for multiple traits measured in
a multi-environment trial (MET) design comprising optimal cultural
conditions and water deficit, salinity and heat stress over 12
environments. Substantial GxE was observed for all the traits measured.
Different plasticity parameters were estimated through the
Finlay-Wilkinson and factorial regression models and used together with
the genotypic means for quantitative trait loci (QTL) mapping analyses.
Mixed linear models were further used to investigate the presence of
interactive QTLs (QEI). The results highlighted a complex genetic
architecture of tomato plasticity and GxE. Candidate genes that might be
involved in the occurrence of GxE were proposed, paving the way for
functional characterization of stress response genes in tomato and
breeding for climate-adapted crop.