Hot off the press!
Authors include RHA member Dave Byrnes at TAMU.
Breeders take note - the paper includes a list of roses that appear to be resistant to RRD and also lists of roses that are moderately and highly susceptable.
Abstract: Rose rosette disease (RRD) caused by the rose rosette emaravirus (RRV) and transmitted by
the eriophyid mite Phyllocoptes fructiphilus (Pf), both native to North America, has caused significant
damage to roses over the last several decades. As cultural and chemical control of this disease is
difficult and expensive, a field trial was established to systematically screen rose germplasm for po-
tential sources of resistance. One hundred and eight rose accessions representing the diversity of rose
germplasm were planted in Tennessee and Delaware, managed to encourage disease development,
and evaluated for symptom development and viral presence for three years. All major commercial
rose cultivars were susceptible to this viral disease to varying levels. The rose accessions with no or
few symptoms were species accessions from the sections Cinnamomeae, Carolinae, Bracteatae, and
Systylae or hybrids with these. Among these, some were asymptomatic; they displayed no symptoms
but were infected by the virus. Their potential depends on their ability to serve as a source of viruses.
The next step is to understand the mechanism of resistance and genetic control of the various sources
of resistance identified.