Growing plants in the stressful Space environment starts from the optimisation of cultivation in soilless systems

The presence of plants on Earth is the result of a continuous process of adaptation to specific environmental factors such as light, temperature and water. In Space, plant growth can be altered also by the action of new environmental factors including ionising radiation and microgravity. The intensity by which these factors are perceived as stressors depends on many conditions as plant physiological and nutritional status. Consequently, the success of plant adaptation to Space depends on the possibility to optimise plant cultivation in Bioregenerative Life Support Systems (BLSSs). In the design of plant-based BLSSs, the main goal is the creation of stable, not-stressing conditions to guarantee plant growth and reproduction for long periods. Within this context, the ESA-project MELiSSA (Micro-Ecological Life Support System Alternative) proposes an artificial biorenenerative ecosystem based on both microorganisms and higher plants. One of the goals is to optimise soybean cultivar (cv) selection and cultivation protocols in hydroponics in order to maximise plant growth efficiency, also reducing plant sensitivity to space stressors.