The invention relates to a rucola plant of the species Diplotaxis tenuifolia which may comprise genetic determinant B and optionally A that leads to expression of resistance against at least Hyaloperonospora parasitica isolates Pp0615 and Pp1248, which genetic determinant B is obtainable from a Diplotaxis tenuifolia plant which may comprise said genetic determinant, representative seed of which was deposited with the NCIMB under deposit number NCIMB 42151 and which genetic determinant A is obtainable from a Diplotaxis tenuifolia plant which may comprise said genetic determinant, representative seed of which was deposited with the NCIMB under deposit number NCIMB 41811. The invention further provides seeds that can grow into a plant that is resistant to at least Hyaloperonospora parasitica isolates Pp0615 and Pp1248, to progeny of the rucola plant, to propagation material suitable for producing the plant, to seed and to parts of the plant and food products which may comprise the plant parts.