Résumé
Adaptation to abiotic stresses is a complex and challenging biological issue for a genetician, especially for perennial plants such as grapevine. According to Copper and Hammer (1996), adaptation is both a “status” and a “process”. The “status” characterizes a genotype with a specific combination of alleles which allows the plant to survive and perform well in a specific environment. The adapted phenotype may result from a constitutive expression of the genotype or from genotype x environment interactions, in other words from the plasticity of traits. This modification of phenotype is referred to as acclimation. Physiological changes underlying acclimation occur over the short-term or over the life-cycle length of the individual. The “process” of adaptation will result from the new combination of alleles over generations to obtain a phenotype better able to survive or grow under abiotic constraints. By definition, the “process” time-scale is the reproductive cycle length. In addition for a crop, an adapted phenotype will include survival, yield maintenance, and especially for grapevine, optimal fruit composition. Considering the economic importance of grapevine, the ongoing and expected climate changes make the issue of adaptation even more challenging. Given the numerous environments where this plant can be found and the huge intra and interspecific diversity, we can assume that the grapevine genome bears many alleles which could be mobilized to “adapt” this crop and maintain its sustainability. The challenge is to identify these alleles and understand how they can be leveraged in manipulating the phenotype. The diversity of abiotic constraints (thermal stress, drought, salinity, mineral deficiency, etc...) and their characteristics in terms of their timing, duration, and intensity need to be taken into account. On the plant side, the traits underlying adaptation and the stage of sensitivity should be clearly defined. Targeted traits are often complex and under the control of various genetic mechanisms. Over the past ten years, there have been numerous achievements in grapevine in genome sequencing, phenotyping, genetic architecture analyses, gene identification, and modeling. Thanks to this new knowledge and technologies, our understanding of adaptation to abiotic stresses has improved and can now be used to screen for particular behaviors in existing germplasms or to breed new ones. An overview of the work performed in France over the past years aimed at adaptation to temperature and drought will be presented.