Perhaps getting a group of cuttings of Rubus chamaemorus this early summer; I’ve read various Rubus will hybridize. In many ways our plain old Rubus trivialis has growth habits very similar to Cloudberry. I’m wondering if they can be crossed and hopefully an easier to grow offspring will happen. {suited to 8B}
I’m not real confident of keeping Cloudberry growing here. Has anyone bred Rubus before?
I have but I don’t know anything about those species. It can’t hurt to try.
Cloudberry and Southern Dewberry
Yeah I got that from the names, no experience or info about them though.
I have one hybridization developed and that’s a purple. Actually nature did it under my nose in my own backyard to remind me nobody does it better. I only crossed blacks and reds with fantastic success but that’s it. My plants are
Irene (pink like Double Gold)
Lynn’s Black ( primocane black with huge berries in both crops)
Sterling Black (primocane black with amazing flavor in both crops)
Sterling Yellow ( trailing ( in full shade) or upright prolific, and hardy yellow)
Drew’s Primocane Purple (discovered in 2019, world’s first primocane fruiting hybrid purple).
I want to work on a primocane yellow cap.
Drew’s Primocane Purple
Will you eventually be distributing the varieties you’ve worked on? 
Yes, not all though. Irene probably not. The others I feel are improvements in at least one thing. I sent out two of Lynn’s Black, hope they make it! I have one in reserve.
I need to make a few copies of Primocane purple, and test it further. Most purples are said to be OK but slightly bland in flavor. Much like black raspberries. This one is not bland and contains a surprising amount of acid. To me it tastes like my boysenberries except sweeter, actually better than boysenberries! I’m kinda biased though so it may be just me. I’m not convinced that’s its a true black raspberry x red raspberry cross. It came up where my tayberries and wyeberries are. It’s 20 feet away from the nearest red raspberry. I guess no way to actually know without a lot of effort. It’s good, hope I can spread it around. Oh also the flowers look and shaped in round clusters like black raspberries so not doubt about that parentage.
Does anyone know how easy it is to hybridize blackberries and red raspberries?
I would think the real problem is that the canes aren’t gonna thicken much at this point, so the tissue won’t be able to heal together well.
It’s easy if you get a tetraploid raspberry (which aren’t easy to find)
Oof, so it’s not something I can just cross pollinate and plant the seeds of.
It’s not especially easy unfortunately.
Raspberries are diploid, whereas most blackberries are tetraploid, and the blackberries that aren’t tetraploid are hexaploid or higher.
I’m currently in the process of trying to get around that by creating some tetraploid hybrids. This spring I pollinated both emasculated Tayberry and Loganberry flower (both hexaploid) with pollen from diploid raspberries. The fruit set and had plenty of seeds, but I don’t know yet if they’ll germinate. If they do, they should mostly be tetraploid and will be raspberry-ish given their parents being raspberry x (raspberry x blackberry). I’ll then be able to breed them with each other to try and select for more raspberry-like traits, and I’ll be able to start crossing with tetraploid blackberries.
Failing that, I may just treat some of my better performing raspberries with oryzalin, but that’s not my ideal route.
Personally, I’m after larger berries with raspberry-like flavor that are sweet and grow on erect canes with the heat resistance of blackberries. Primocane-fruiting would be nice, but it’s not a priority.
I’m also working on raspberry x mysore crosses and am similarly waiting on germination from them. With those crosses, my immediate goal is for a very heat resistant purple raspberry with good flavor and sweetness and ideally the upright habit and beautiful color of mysore canes. If I like what I get in the F1 or F2 generations, I might also tetraploidize them (either by crossing with a hexaploid or with oryzalin) and use them in the blackberry crosses, especially since I expect the berries will be quite small and it might be hard to get them bigger while keeping a high proportion of mysore genes.
Not on the subject of tetraploids but on the subject of hybrids, I also got Dorman Red raspberry this year. Dorman Red is a hybrid of 75% Rubus parvifolius and 25% European red raspberry. It’s heat resistant and productive here in the South, but the berries are small and universally described as flavorless.
Next spring I’m looking to backcross it to Bababerry and perhaps Heritage. The goal would be to get some flavor, larger fruit size, and upright growth habit bred into it. Again, I suspect it’ll take a few years and generations to actually get there.
In some ways the Dorman Red project is a duplicate of the Mysore project, since in both what I’m really trying to do is breed heat resistance into European raspberries. And honestly the tetraploid hybrid project has basically the same goal as well, just with blackberries providing the traits rather than subtropical raspberries. But I’m not certain any one pathway will get me what I want, and each one of these have interesting possibilities if they do work.
How exactly does the oryzalin work in doubling ploidy? How would I go about it if I wanted to?
I’d be curious how any of your results turn out in your crosses.
If for instance I still tried crossing a diploid raspberry and tetraploid blackberry, would it be possible to still get a triploid hybrid? And if I got a triploid hybrid it probably would be sterile, but would it still be possible to get a occasional seed that is diploid kind of like you can with seedless watermelon?
I don’t recommend this route haha. Oryzalin is a potent toxin that inhibits cellular mitosis. At just the right dosage, it can sometimes cause chromosome doubling, tripling, or other weirdness, so you get cells that are a mixture of different ploidies. The idea is you treat plants in tissue culture, grow them out, and select the ones that ended up tetraploid. You can also treat seeds and seedlings (which is what I have to do because I don’t have the set up to culture stuff yet), but it’s less effective.
I guess so, but I don’t think it’s ever happen before.
All raspberry x blackberry F1 hybrids have been hexaploid. To the best of my (inadequate) knowledge, no one has ever gotten them to do what you’re describing. That might be because they didn’t grow out enough triploids, but honestly it seems like it’d require an unrealistic number of crosses to work. Even just the hexaploid hybrids required huge numbers of crosses before it worked.
How can you figure out the ploidy? Do you have to experiment if it can cross?
Tetraploids can often be visually identified. I’m not sure yet how it’ll be with Rubus, but with citrus tetraploids have thicker stems and can have wider, sometimes crinkled leaves, and with passionfruit the stems, leaves, and flowers are significantly larger most of the time.
Roots also tend to be thicker.
The easiest way is to send leaf samples off to a lab for flow cytometry analysis.
I have a feeling that will get expensive if I want to test a hundred seedlings. How much does it cost per test?
$20 each for 10 or more samples, so one hundred would get pretty expensive.
