I have also found mention of Fragaria x Rubus (Raspberry) actual working out online.
https://the-biologist-is-in.blogspot.com/2015/01/hybrid-sterility-and-speciation.htmlhttp://living-mudflower.blogspot.com/2018/04/strawberry-raspberry-hybrids.htmlhttp://living-mudflower.blogspot.com/2018/07/strawberry-x-raspberry-hybrid-plant.htmlhttp://living-mudflower.blogspot.com/2019/02/strawberry-x-raspberry-experiment-update.htmlhttp://living-mudflower.blogspot.com/2019/02/strawberry-x-raspberry-intergeneric.htmlhttp://living-mudflower.blogspot.com/2020/07/strawberry-raspberry-hybrid-plants.htmlhttp://living-mudflower.blogspot.com/2020/09/raspberry-x-strawberry-hybrid-f2-seed.htmlhttp://living-mudflower.blogspot.com/2021/05/strawberry-raspberry-hybrids-test.htmlThis is quite interesting to me. The fact that they got the plants tested is even better. Unfortunately I don't have Fragaria vesca plants at the moment.
It should work with F. vesca and R. occidentalis as well. So I might not need a red raspberry.
The R. occidentalis in my area has the white / reddish stems. Even other types usually have blueish stems. R. idaeus has green stems. Not to mention the whole black - blue colored fruit. Even the Yellow Black Raspberry could prove interesting in a cross.
R. occidentalis would be of more interest in breeding to a F. vesca than just purely to R. idaeus. A strawberry with anthocyanin would be interesting.
Making crosses with R. idaeus types from North America and Europe - along with others that have the same ploidy would probably be very nice. Same thing with F. vesca.
This would allow for the best flavors / disease resistances of both parents.
From what the Living-mudflower blog has said, the hybrid appears to somewhat perennial based, same with the Fragaria parent. Runners probably produce even more F1 clones. Quite a nice thing for breeding purposes. The plants don't fruit untill around the second year - same as raspberries.
The hybrid should have sugars from both parents according to the Living-mudflower test results. Also seems to be very "tasty". Selecting the tastiest varieties from both species should give excellent offspring.
Now to mention possible issues:
The first one would be that in this cross, the plants all seem to have mostly Fragaria characteristics. This could be due to a number of reasons - one of them could be that most of the Rubus genes get skipped over and reverted to the Fragaria type. Something similar happens with Female Mule x Male Donkey hybrids - most of the Horse genes are replaced with Donkeys.
Could of course be that the Fragaria genes are carried over mostly by the mother, most of the Rubus genes are skipped over right away. Living-mudflower mentions this as well, along with a related source:
www.fao.org/3/a-y5553e.pdfThis may feel familiar to others on here - Solanum chilense's root system is maternal based. Some other wild tomato species behave this way as well.
This could mean that certain disease resistances may not transfer over - or things may end up sterile at higher rates in certain generations. Most diseases/pathogens attack certain genes, having a target gene cross over to Fragaria species without the resistance / immunity could cause the pathogen to adapt and start attacking other Fragaria species(Or Rubus species). Of course the last part could happen even if the resistant gene is present.
R. occidentalis plants usually need pollination from other plants, there are Fragaria species like this as well - might help to maintain diversity / traits from both parents. Unsure if the female / male mechanisms are the same/compatible though. If important genes are being skipped over due to maternal related genes, backcrossing may work - hopefully in either direction.
Mixing in different species that have different ploidy counts would be nice as well. But then the cross may not work very well - would probably need to have the plants tested to try and restore the ploidy along the way.
This falls out of the general "Rubus" hybrids category, I don't really want to make a thread about something that I may not even experiment with or that people have no interest in trying. Seems like Andrew commented on one of the post on the Living-mudflower posts about the hybrid. So there might be a small bit of interest.
I might buy some seeds, start some late strawberry plants which should flower a bit next year. There are some feral F. × ananassa plants flowering right now at the same time as R. occidentalis. Just need to make sure that the F. vesca variety that I plant is early enough.