I have found this fact myself, and in two other sources that if a diploid rose is heterozygous for reblooming/ once blooming is bred to a reblooming rose only 1 in ten will be reblooming not the 1 in 2. One argument is that the reblooming seedlings die but I do not loose that many seedings. Any ideas?
Johannes,
I’ve also noticed that rebloomers were very under-represented in a population of open-pollinated seedlings of F1 (multiflora X ‘Mutabilis’) which should be heterozygous for rebloom. I had figured that by selfing (or backcrossing to ‘Mutabilis’ which was growing next to the F1 hybrid), I would find at least 25% rebloomers. In actuality, I only found 2 reblooming seedlings in a batch of 40 - 50 total.
From this and also some other observations, it appears to me that inheritance of rebloom in roses is a very complex matter. It’s definitely not just a case of a simple dominant/recessive pair of genes.
Tom
Wow Tom, that sounds like a very interesting cross- R. multiflora x Mutabilis!!! Did some of the warm colors come through?
I found that in general the standard inheritance of the repeat bloom gene holds true, but I suspect that there are other genes that modify its expression or other genes that can compete and are inherited differently perhaps. I have a seedling of R. virginiana x R. laxa that reliabily has a later bloom like R. laxa (better than laxa even). That has been transmitted to a second generation of this interspecific with a modern rose. It seems like this factor is dominant. Nothing else has trumped the one time bloom alleles in this R. virginiana clone before.
On the other hand, I’ve been disappointed with the many poor repeaters or maybe even one can call them one time bloomers coming from ‘Robin Hood’ and its descendants crossed with strong repeat blooming polyanthas and other roses. Sometimes once they are more mature they repeat or repeat better, but not always. I had a lot of stringy long seedlings on the plant stand that did not bloom tracing back to ‘Robin Hood’. Many hooked my clothes as I worked with them this past winter and get pulled from the trays. After a year and they get their first winter then they bloomed well in the spring and repeat bloom better. When I root cuttings they sometimes tend to be long and stringy again without much bloom until they get a winter and seem to maybe be induced to bloom better again. I don’t understand it.
Sometimes it’s discouraging when things don’t work out the way we expect and hoped for. Good thing we still some repeaters to work with. With the limited resources most of us have it’s harder to get the numbers to sort through to find the good repeaters.
Sincerely,
David
I have another example. I have a friend who sent me literally hundreds of hips of Kim’s, ‘Indian Love Call’. Out of over a thousand seed sown and and a few hundred resultant OP seedlings, I got exactly two remontant seedlings.
Up to half of these should have been remontant. Obviously inheritance of remontancy is not as clear cut as one would assume.
I think that there is a saying: “work toward a good plant first and then screen for flower form”. More and more I feel like revising that statement to: “select for repeat bloom, then plant health and hardiness, then growth pattern, and then last for flower form”.
Henry said.
“select for repeat bloom, then plant health and hardiness, then growth pattern, and then last for flower form”
I absolutely agree Henry. That’s exactly what I’m doing.
David Zlesak wrote: …very interesting cross- R. multiflora x Mutabilis!!! Did some of the warm colors come through?
The buds are just a little bit peachy, but open white. The flowers do get a little bit pinkish again with age (especially at the center-almost like a faint Hulthemia eye pattern), but overall, I wouldn’t say it got too much of the ‘Mutabilis’ flower coloration. It did get the dark-purple new growth and China-like foliage, but with the long arching canes of multiflora.
And I agree with Henry’s strategy too…
“select for repeat bloom, then plant health and hardiness, then growth pattern, and then last for flower form”
One of David Ziesak’s R virgiana X R laxa seeds from several years ago has produced a plant: what are the odds that this plant will eventually be fall-remontant?
An important breeding goal for me is to produce plants which bloom in spring, rest all summer, and then bloom heavily in fall. Producing blooms during summer is a waste of the plant’s energy: summer blooms are ravaged by heat and jap beetles, in this part of the country.