The apple cultivar Regia, bred in Dresden-
Pillnitz, Germany, is one of the few cultivars originating
from a different scab (Venturia inaequalis) resistance
background than Malus floribunda 821, the source of
Rvi6. Cv. Regia is a descendant of Russian apple
R12740-7A and has been proved to contain the two
scab resistance genes Rvi2 and Rvi4. The cultivar itself
has been grown in Dresden-Pillnitz since the early
1970s, while seedling populations derived from cv.
Regia have been raised in fungicide-free plots since at
least 1982. In 2011, small scab lesions were found for
the first time on leaves of cv. Regia trees in an experimental
unsprayed orchard in Dresden-Pillnitz. Single
spore isolate Regia2 (R2) was cultured from these scab
lesions and propagated, and then inoculated on scions of
the VINQUEST scab differential host set comprising
host (0) to host (15), host (17) and cv. Regia, grafted
on rootstock M9, in a greenhouse. Strong sporulation
was observed on hosts (0), (1), (2), (8), (9), (10) and cv.