'New Dawn' hybrids

[Warren]

I hope I am not thread jacking here. I have applied Therese Bugnet pollen to three F1 Virginiana hybrids and to the SetipodaX Carolina Hybrid. I am aware this will delay having repeat blooming cultivars for a few years, but should produce some reasonable cold tolerate cutlivars.

Warren

[Rob_Byrnes]

Paul,

Thanks for sharing your experience with CG’s fertility.

Rob

[davidzlesak]

I love the color of the large single too. It does rebloom like ‘Therese Bugnet’. ‘Catherine Guelda’ blooms more continuously more similarly to a polyantha.

[Judith_Singer]

That seedling, Catherine Guelda, is beautiful!

[Don]

I agree with Judith, Catherine Guelda is a very pretty plant judging by the photos on HMF. Did you commercialize it, David?

[Karl_K]

@pgeurts

Karl,
One would think that from a purely theoretical perspective it shouldn’t make a difference to eliminate the rugosa “weak neck” whether they first crosses a rugosa with an R.blanda or not. In both cases the F1 would have one set of genes from the Rugosa for the “weak neck” and one set genes from the other parent without the weak neck. Crossing one of the F1s from either scenario to another plant without the “weak neck” should result in 50% of the offspring without any genes for “weak neck”. But there may be some linkage to hardiness or disease resistance that was being selected for so the weak neck just happened to be selected for also. Another possibility is that the rugosa “weak neck” may be more dominant over the genes for straight neck in the moderns than it is over the genes in R.blanda. Further study will need to be done to clarify this.

I agree that more research is needed. And it is the possible linkage that is the issue. If we assume, as you suggest, that the Rugosa genes related to weak neck, hardiness and or disease resistance are linked on the same chromosome, it would be necessary to cross Rugosa with some other species that has a chromosome that will pair well with the Rugosa chromosome in question and allow reassortment. Otherwise, the Rugosa genes might remain linked as a “supergene” when backcrossed with HTs, Floribundas, etc.

An example of this sort of linkage occurs in the genus Rubus. Blackberry prickles vary in thickness, length and color. So do the prickles of Raspberries. If one crosses Raspberry x Raspberry or Blackberry x Blackberry, the various prickle-traits re-assort. But in a cross of Raspberry x Blackberry (or reciprocal) the prickle traits are inherited as a linked group.
http://bulbnrose.x10.mx/Roses/Hurst/DarlingtonVersatility1949.html

Similarly, in various Pernetiana lines, bright yellow may be linked with globular buds, or with a tinge of red.
http://bulbnrose.x10.mx/Roses/breeding/Legrice/Legrice1.html

Karl

[davidzlesak]

Hi Don!

Pat Henry at Roses Unlimited sold it for a few years. Also Brentwood Bay had it for a bit. Maybe Pat still has some available if people want GC. It was named for a the daughter of a good friend, Dr. Jeff Gillman, who liked purple.