Adaptation of perennial alfalfa genotypes to the outside oasis environment in order to improve the performance of the southern Tunisian agro-system

Alfalfa breeding in areas with high abiotic constraints has made little progress in improving productivity and tolerance. The difficulty lies in identifying and characterizing the parameters related to resistance to different climate pressures. Various phenological, morphological, physiological and chemical processes are the origin of avoidance and tolerance strategies. The purpose of this work was to study the morphophysiological and chemical divergences between eight perennial alfalfa genotypes from different origins: 3 native genotypes (IRA, Gabès, Chenini) and five exotic ones (Ameristand, Bami, Prosementi, Tamentit and Tata) exhibiting a high tolerance to the arid bioclimate outside oasis. The obtained results allowed to classify the genotypes into two sufficiently homogeneous groups which could be considered as an interesting breeding genetic pool for the chosen selection criteria. This pool is the starting genetic material for the creation of synthetic varieties adapted to arid conditions outside oases characterized by higher fresh and dry yields (Ameristand, Bami, and Tamentit), with excellent tolerance to salinity (Gabès and IRA).