Isolation, taxonomic analysis, and phenotypic characterization of bacterial endophytes present in alfalfa (Medicago sativa) seeds.

•Forty different bacterial genera were found as seed-endophytes in alfalfa.•Seed endophytes presented in-vitro activities related to plant-growth promotion.•Many isolates of the identified genera were found as alfalfa-plant endophytes.•Alfalfa seeds are natural carriers of (likely selected) bacterial inocula to plants.