Seed priming by application of Microbacterium spp. strains for control of Botrytis cinerea and growth promotion of lettuce plants

•Volatile-producing Microbacterium spp. inhibit in vitro growth of B. cinerea.•Microbacterium spp. mitigate gray mold damages on lettuce by seed priming.•Volatile-producing Microbacterium spp. stimulate the germination by priming.•Microbacterium spp. promote plant growth on lettuce seedlings by seed priming.