Did anyone try this rose in hybridizing?
I was at the Lens nurseries in Belgium last winter and they have a kind of show garden there. Lots of hips and I took a few of Scharlachglut. Two seeds have germinated and one seedling has two buds!
Now, I should be able to answer this question myself, but it just doesn’t hit me, so: Scharlachglut is HTxgallica. If it would pollinate itself, would you expect rebloom? Or does the rebloom mean something else pollinated it? I hope more seeds will germinate. Maybe I can get a hint at the frequency of rebloom occurrence.
I also took seeds of other roses, but I put them all together (stupid!), I only know this is Scharlachglut offspring because they came from huge buds, and the seeds are huge. I also had some small seeds and they are germinating too. I remember getting small buds from R. x dupontii. Does anyone know if this hybrid is fertile (i.e. is it possible I have germinating seeds from this rose)?
The fact that it has bloomed so early could very much mean that it is a repeat blooming rose. So two possibilites are that it pollinated by itself or with the pollen of another rose with at least half remotant gene.
Assuming tetrasomic inheritance, there would be 1 in 36 chance that a self-pollinated Scharl. seedling would be a rebloomer, and if outcrossed to a repeat bloomer, 1 in 6. Scharlachglut is a single flowered rose. That trait is recessive. So, if your seedling has double flowers (say consistently greater than 7), that’s a good indication it is a seedling from outcrossing. If it is single flowered, it could still be either.
My R.x dupontii makes seeds that germinate readily, though the seedlings are usually kind of weak and uninspiring (I’ve kept a few around over the past couple of years in my seedling beds). I also have done successful crosses with it, though it seems harder to work with that way. I love the bush–it’s a real standout in my species rose bed–but it does get pretty significant Blackspot here. Still the flower is gorgeous.
An update: more Scharlachglut seedlings germinated so I should have ten plants or so, if they all survive. The seedling I wrote about has three buds plus two side buds for every main bud, so nine in total! I removed all side buds and left two main buds. I put the plant outside, but saw some blackish spots on the lower leaves so I put it in the greenhouse again. I hope it’s not blackspot! The leaf still looks healthy though.