used a high density single
nucleotide polymorphism (SNP) map in a bi-parental
mapping population segregating for the dominant
monogenic resistance to CMD, and found a single
locus with large effect, which is probably the CMD2
locus. In their study they found nearly half of the
progeny and the female parent to be resistant to CMD,
with the remainder of the F1 individuals showing
disease symptoms ranging from mild to severe