Glomus iranicum var. tenuihypharum var. nov. strain deposited under BCCM deposit number 54871, comprising the sequence identified by SEQ ID NO: 1; composition comprising said strain and 2:1 smectite clays and use thereof as bio-stimulant. The invention also discloses a composition comprising said strain, fungicides, bio-fungicides, insecticides, bio-insecticides, nematicides and bio-nematicides.