Program, Symposium Rose Research and Cultivation

Courtesy of Dave Byrne, the program(me) of the Sixth International Symposium Rose Research and Cultivation.

Hi Don

There is a communication you coauthored me and all of us are interested in:
Its introduction last words being:
“the study will help rose breeders determine the needs of both growers and consumers and the direction of future breeding projects.”

Could you let us know the full contents?

Please note: “Macerating the seed coat with 0.5% cellulase for 50 hours produced the best germination response among the studied pre-stratification treatments
Detailed experiments on various regimes of warm and cold stratifications are currently underway.”


Holy cow! Information overload. That would have been such a fun conference to go to, despite a lot of it being over my head.

It was wonderful!! RHA members Jim Sproul, Dave Byrne, and myself went. The tours of Kordes, Tantau and a government facility that does comparisons for plant breeders rights and hosts an ADR trial were incredible. There were many wonderful presentations and posters. It was a wonderful networking opportunity to get to know others and their work. There were many wonderful things shared. As time goes by Jim, Dave, and myself would like to write articles for the RHA newsletter. Some very disappointing news is that rose rosette was reported to now be in Europe. The exact location will not be disclosed until Dr. Ioannis Tzanetakis’ paper is in print. Researchers are understanding the sequence of the major repeat bloom gene in greater detail. As known, is just a knocked out gene with lower expression for the need of vernalization (cold) for the plant to bloom. THere are different alleles of it that the French research group have identified. They key one if I remember right out of R. chinensis has a very large transposon in the middle of it interrupting its expression. There are other alleles are from different backgrounds. I have to review my notes, but there is one out of what I remembered to be R. multiflora background with a different length and maybe placement of the disruption in the gene. For years I suspected the Angel Rose polyanthas seemed to be straight multiflora background without Chinensis background because of their morphology and full fertility with R. multiflora and that there shouldn’t be any reason for that major gene to be knocked out and disrupted in many rose backgrounds. As we read some, generally popular, rose literature authors seem to love to emphasize the Hybrid China roses as the only source of repeat bloom in our modern roses. There of course are minor genes involved too for degree of expression of repeat bloom.

THere is a lot more to come, so stay tuned. We will be be providing some nice summaries of advances we learned in the upcoming RHA newsletters!!

David Zlesak

Regarding rose rosette virus in Europe (and possibly, even elsewhere) there have been a number of reports of rose witches bloom in Poland (and even one in China). These were thought to be of phytoplasma origin (as some scientists in the U.S. thought that rose rosette disease was). Now that the PCR test is available I assume that these possible phytoplasma infections are being tested for the virus."rose+rosette"&btnG=&as_sdt=1%2C5&as_sdtp=

Pierre, thanks for asking. Here is a link to the Powerpoint presentation delivered by Dave Byrne on behalf of senior author Tina Cade and me.

The presentation focused on some of the data we gathered in our survey research project Roses for the 21st Century. Other papers based on that data are in the works and the survey results themselves will be put on the website after I get it fully restored.

Was this the German study referred to earlier in this thread?