Patent ID: 8119856

Claim:
An onion or shallot plant of the Allium cepa species which is resistant to downy mildew of onion caused by the fungus Peronospora destructor (Pd), which plant comprises a Pd resistance locus present homozygously in the long arm of chromosome 3 in the genome of said plant, the Pd resistance locus having a sequence identical to a genomic segment of Allium roylei conferring resistance to downy mildew in A. roylei , wherein the Pd resistance locus comprises a 61 nucleotide amplification product with the selective amplification primers: 5′-GACTGCGTACATGCAGAAC (SEQ ID NO:5) and 5′ GATGAGTCCTGAGTAACTT (SEQ ID NO: 6) in the genome of said plant restricted with restriction enzymes PstI and MseI; and ligated with the following oligonucleotide adapters: alpha 5′-CTCGTAGACTGCGTACATGCA (SEQ ID NO:1) CATCTGACGCATGT-5′ (SEQ ID NO:2), and beta 5′-GACGATGAGTCCTGAG (SEQ ID NO:3) TACTCAGGACTCAT-5′ (SEQ ID NO:4).