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Phenotyping for the response to drought and high temperatures in a diversity of scenarios
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Edité par CCSD -
The plant science community has to design new genotypesthat are able to cope with the diversity of environmental conditionslinked to climate change. A major issue is to combinegenomic selection with knowledge originating from phenotyping.We have adopted for that a multi-scale multi-environmentapproach. In the field, it consisted of clustering time courses ofenvironmental variables over Europe into six scenarios of temperatureand water deficit experienced by plants; of performingfield experiments in 29 contrasting environmental conditionsacross Europe with a panel of 250 maize hybrids; assigning individualexperiments to previously defined scenarios, and finallyanalysing the genetic variation of plant performance for eachenvironmental scenario via genome wide association studies(GWAS). Large variations of QTL effects depending on environmentalscenarios resulted in a pattern associated with eachQTL. In a phenotyping platform (Phenoarch), we have estimatedintercepted light and radiation use efficiency of each hybridof the same panel via a functional-structural model using 3Dreconstructions of each plant, and the sensitivity of growth towater deficit of each hybrid via a joint analysis of several experimentswith contrasting light, evaporative demand and soilwater potential. As a whole, the combination of field and platformapproaches results in a dataset that allows one to identifygenomic regions associated with tolerance in specific scenariosof heat and drought, and with traits associated to thesegenomic regions. Finally, models allow identifying geographicalregions in which a given combination of alleles is likely to havecomparative advantages.