Genetic variability of plant responses to evaporative demand and water deficit, a forward integration from phenotyping to simulation of plant performances in the field
Résumé
Crop improvement for drought is based on the selection of alleles
that increase yield in dry or hot conditions. The Genotype
by Environment Interactions (GxE) is typically high in these
environments, with alleles conferring either positive or negative
effects, depending on drought scenarios (Tardieu, 2012).
Rather than trying to over-simplify GxE, for instance, in managed
drought experiments, we propose an integrative approach
using genome wide association studies (GWAS), phenotyping
and modelling. It aims at predicting in which drought scenarios
a combination of trait/allele could confer advantages (Parent
and Tardieu, 2015). Indeed, (i) we phenotype the intra- and inter-
specific variability of development and growth responses to
temperature, evaporative demand and water deficit with phenotyping
platforms. (ii) We develop ecophysiological models with
parameters which can be directly extracted from measurements
in platforms and in the field. (iii) We carry out GWAS at different
scales, from -omic to plant scale in platform, and to yield components
in network of field experiments to identify QTLs linked
to conditional allelic effects depending on environmental conditions,
and to values of model parameters. (iv) We use either
direct measurements or the allelic compositions at target QTLs
to determine the phenotypic profiles (set of parameter values)
of real or virtual genotypes. (v) We simulate genotypic performance
and the contribution of genomic regions under current
and future stress situations over Europe via modelling. Results
are compared to the observed genetic variability in networks of
field experiments and are used as feedbacks for improving our
phenotyping routines and ecophysiological models.
Mots clés
Domaines
Biologie végétale
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