Thanks Rob. Let’s hope that’s only half of the story.
Did you use something modern as the other parent? Was Cardinal used for seed or pollen?
Thanks, Robert
Mine are all OP seedlings Robert. CH has a VERY interesting ancestory so I think it has much to offer as a parent.
Thanks Rob. I think so too. I’m using a CH sport I discovered. It has increased petal count. It almost resembles an Austin.
On the subject of using triploids in breeding programs… is it a waste of time/effort due to infertility issues? If not what’s the best strategy to improve your chances of success?
Simon, some of my best breeding stock are triploid. Every case is different.
Some triploids are quite fertile and others nearly sterile.
If known triploids have a history of fertility, your question is answered. Otherwise it’s trial and error.
Thank you for that link Robert. I LOVE the look and color of that Cardinal Hume sport. Are you the one who found it?
Yes, I found it.
Strangely I didn’t realize it was a sport for some time. Then one day it hit me. It’s quite different.
I’ve using Cardinal Hume as a substitute rootstock for Dr. Huey. It works quite well.
This sport popped up in a batch of cuttings destined for understock. It’s amazing I didn’t bud anything to it and lop the top off. I would have never known.
Now I have to figure out whether anyone is interested in this sport except me.
Does Dr Huey set hips naturally?
A few, each with one or two or three seeds inside (maybe someone has seen hips with more). One year (maybe about 1980) I harvested 5-6 OP hips from a good sized plant–got 10-11 seeds, of which zero germinated.
Peter
Would it be fair to assume that low OP seed set may indicate low fertility or does it just mean that it has low ‘self’ compatability?
Your sport is one that I would buy Robert. You should think about introducing it.
Rob
Triploids are like roulette. I love it, lol.
“Would it be fair to assume that low OP seed set may indicate low fertility or does it just mean that it has low ‘self’ compatability?”
Many OP are not self pollinated.
Then another case of no OP hips is lack of active pollinator.
I.e. the actually much used The fairy that has no OP hips in many gardens. However is fertile when compatible pollen and active pollinator are available.
“On the subject of using triploids in breeding programs… is it a waste of time/effort due to infertility issues? If not what’s the best strategy to improve your chances of success?”
Years ago I did a lot of triploid breeding and allmost ceased.
Why: lower efficience.
With the failed at developing hips and lower germinability average number of germinated seeds/cross made is often not bigger than 1. Add to this that only a few seedlings from triploid pollen or hip are fully fertile.
However I did see The Fairy loaded with tags in some commercial firm breeding fields and TF appears in many recent pedigrees.
My triploid Banksia hybrids are quite fertile.
I did get some OP hips from ‘The Fairy’ here and the seed germinated easily but the seedlings were undistinguished. I never made any direct crosses.
I had some OP ‘The Fairy’ seeds this year that have come up and are at the three/four leaf stage. Only one seed per hip though but quite a few hips.
I’m amazed how foundational ‘The Fairy’ and ‘New Dawn’ are in modern disease resistant cultivars- as direct parents or in the background further back. ‘The Fairy’ is diploid. ‘The Fairy’ seems to have limited fertility probably because of its diverse background. It seems to work better as a female. I’ve had trouble getting pollen from it.
Sincerely,
David
I am actively using 2 triploids in my hybridizing. Golden Glow and Glenn Dale. Not sure about the ploidy on Glenn Dale but am assuming that its a triploid.
I still have a nagging question in the back in my mind about fertile triploids. Are fertile triploids more likely to produce fertile triploids when crossed with diploid roses. When I say more likely, I mean more likely when compared to tetraploid x diploid crosses.
I had intended to experiment with this over that last 2 years but never found the opportunity. Next summer will be my first experiments. Ross Rambler (which turns out to be a diploid) and maybe r. acicularis nipponensis are going to be my first subjects. I think Out of Yesteryear is a triploid and it has created some at least partially fertile triploid offspring. I think Tangerine Jewel is a triploid and I have had tons of OP seed set with it. Very low percentage of germination though. So perhaps mating OoY with RR and r. acicularis n. would be interesting as well.
One big goal next year will be to get Golden Glow x Ross Rambler hips.
Simon and Steven,
See link below about a thesis that describes experimental crosses with roses of different ploidy level and the ploidy of the resulting seedlings. The author also freqeunts the RHA forum.
Rob
Link: www.rosehybridizers.org/forum/message.php?topid=8725#8725
Interesting the ‘Golden Glow’ is triploid. Moore uses it a great deal.
I’ve been using Goden Glow’s first generation offspring, ‘Goldbusch’. It’s listed as a hybrid Rubiginosa, Shrub.
I wonder if it’s tetra?