The identification of new variability represents a major tool to face challenges to overcome global warming and improve farming system sustainability. Turnips and cabbages, which largely contribute to food production worldwide, are native of the Mediterranean basin. Wild forms and landraces grow under highly contrasted environments. Taking advantage of this distribution, the objective of BrasExplor is to collect, explore this wide genetic diversity of wild and locally cultivated forms, after discussions with farmers on cultural practices and traditional uses, in order to promote local varieties. Collects will be performed along the climatic gradient with a precise description of contrasted environmental conditions, edaphic and microbiome composition of the soil. From 100 populations of cabbages (Brassica oleracea) and 100 of turnips (B. rapa), we will sequence (Next Generation Sequencing) in bulk each population for genome-wide scans looking for associations between nucleotide polymorphism and environmental variables as well as soil composition in order to search for genetic determinants of adaptation to suboptimal conditions. These data will be confirmed under controlled conditions for water and temperature stress and in contrasted field conditions for different traits: seed germination, root architecture, flowering phenology, self-incompatibility, microbiota diversity, morphology. Genetic data will be also used to infer their population genetic structure and to understand the relationships between the wild and cultivated forms of each species, the impact of farming practices under environmental constraints. Results will allow development of core-collections for in situ/on-farm management strategies and ex situ conservation as well as for promotion of landraces and for first proposal of pre-breeding populations.