Available from - High Country Roses
highcountryroses.com

Saw this beautiful knockout rose at my garden center with many blooms on it with thick petals.

In 2015, the group began three-year replicated trials in Tennessee and Delaware. These trials use augmentation, a process by which RRD-infected plant material is placed in contact with the healthy plants to test for resistance.

“We’re actively trying to get them infected,” Byrne says. “Basically, they take infected shoots with lots of mites and put it on the test material to hopefully get the mite to transfer and pass on the virus.”
This is from Nursery Management oneline:

This is done two or three times per year. Some of the more susceptible roses showed symptoms in three months. Christian Bedard, research director and licensing manager at Weeks Roses, says one of his company’s roses is primed for a breakthrough after five years of testing in Tennessee, including two years of the augmentation trials.

“We’ve given plants to a professor at the University of Tennessee and he’s been trying to infect the plant with the virus for two years and he hasn’t been successful,” Bedard says. “With all the testing we’ve done, it’s shown to be rose rosette resistant.”

The new rose from the California breeder is called Top Gun and it will be available in 2018.