I suspect the offspring of such a cross would have reduced fertility/fruit set due to trouble with meiosis.
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Very well actualy. I planted a few in the flowerbed out front, I replaced a strawberry planter at the community garden with some and the rest are in a bin in the back waiting for me to do something.
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Merva would be interesting, but Iāve never seen it available anywhere.
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Rubus ulmifolius is the oddball but if I recall it was the western trailing blackberries that completely failed to pair with it. They did use r. ulmifolius to transfer the gene for thornlessness to eastern blackberries so that cross should be relatively doable.
I recommend you to look up anything you can find on Loganberry, Black Logan and mammoth. That should give you an idea what to expect from polyploid hybrids.
Many of the higher ploidy varieties are allopolyploids. They have sets of chromosomes that donāt even pair with each other, much less with other species. Aughinbaug, the octoploid progenitor of Logan for example would pass on 4 sets of chromosomes, two of which are typically blackberrylike and two are from an idaeobatus ancestor. It would look something like Bb1-bb1 and bb2-bb2. Two sets from blackberry genome 1 and two sets from blackberry genome 2. Now Logan would have those and one more set from red raspberry and looks something like this bb1-bb1, bb2-bb2, rr-rr where rr represents the red raspberry genome.
Blackberry genome 2 as far as I know can pair with the red raspberry genome but donāt quote me on that. Iām not a genetist and Iām just going with what Iāve read so far.
Fragaria moschata has an equally complex chromosome makeup and according to literature only pairs with fragaria viridis to any reasonable extent. I would suggest you to try a proven route like that to first arrive at a tetraploid strawberry and go from there.
The same can be done with Logan and Tayberry. Just cross it with a diploid red raspberry and you should end up with a tetraploid. Logan would pass on blackberry genome 1 that has nothing to pair with, but possibly blackberry genome 2 from rubus ursinus and certainly the red raspberry genome can pair with a diploid red raspberry.
You could then end up with rr-rr, bb1ābb2, where both blackberry genomes would be forced to pair imperfectly resulting in partial sterility. Now if you are able find partially fertile plants and make an f2 generation you could in theory get fully fertile tetraploids to cross with just about any higher ploidy rubi. Maybe even a strawberry if you get real lucky.
I hope that makes any sense. My point is it might be a good starting point to start hybridizing within the genus to get an idea how high (low) the success rate is with interspecific hybrids and only then start planning completely novel combinations. Also donāt believe everything you read on the internet. I could be completely wrong and you might just end up achieving something new and exciting. Nature can do strange things and chromosomal behaviour is hard to predict.
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I wonder if you could pollinate a musk strawberry (6x) with potentilla palustre (6x) and get purple flowered musk strawberries. That would butcher the aroma but seems worth trying.
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If I get a hold of the P. palustris Iād be willing to try. I think the very tall flower stems and saturated flavor of musk strawberries could help the hybrids be more worthwhile than the current existing hybrids with their bland fruit and short flower stems.
By the way, the resulting plants would almost certainly still need chromosome doubling to have good fertility, but would be very beautiful at a minimum.
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I found some growing in a ditch not too far from here.
Not my picture but this is what they look like
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This guy has all of the arctic raspberries some rare black rasps, a rare purple rasp some rare reds and alot of other hard to find cane fruits. He doesnt shipā¦ someone near NY would have to get a group buy going.
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I have bad news about getting self fertility from an arcticus-spectabilis cross.
āKeep, E. 1968. Incompatibility in Rubus with special reference to R. idaeusā
Says that rubus spectabilis is self incompatable also.
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Iām gonna try it. I have several seed accessions of both in the freezer. I just wonder what the magical breeding combination would be for a tasty berryā¦ hawaiensis woube considered a decent berry, were it not for the bitter component thatās universal in this species. And apparently, the breeding efforts using it invariably resulted in bitter berries in the hybrids. How many generations would have to be backcrossed to spectabilis in order to get a berry that lacks the bitterness? And would such a recursive backcross end up reverting to the comparatively mild flavor of the salmonberry? Or could careful breeding give the flavor of the Hawaiian berry without its bitterness? Regardless, I got plenty of seeds, so it seems like a good direction to try.
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For those interested in crossing Fragaria with Rubus, I was able to find a couple of tetraploid options in the USDA collection which Iāve requested. If they send them to me Iāll propagate and share with anyone seriously interested in breeding (rather than having everyone independently make requests to the USDA).
The advantage of a tetraploid Fragaria is that when hybridized they will have two sets of chromosomes which can pair evenly with each other in the resulting hybrid. Unlike higher ploidy Fragaria species they probably would not dominate the morphology of the progeny since any tetraploid (or higher ploidy) Rubus parent would contribute 50% or more of the genome to the resulting progeny.
One of the tetraploids is a chromosome doubled clone of an improved F. vesca. The other is a naturally tetraploid wild selection of F. tibetica which produces hermaphroditic flowers and runners (typically this species would be dioecious).
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Sign me up if you manage to get any. Last time I tried for the tetraploid vesca, I was told it had died and was thus lost to the collection (this despite the fact that the listing remains active on the website). Iām hoping itās just a mistake, but who knows.
In the meantime (and despite the probable complications), Iām thinking of trying to pollinate Fern (a typical octaploid ananassa) with pollen from the tetraploid Prime Ark Freedom. Iāll soon be getting F. x bifera from the USDA collection, so Iām gonna keep my vesca seeds in the freezer for a little while longer, and cross the bifera with my Capron moschata.
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Hopefully they were able to restart it from seed since it was a chromosome doubled form of a cultivar that does grow true from seed (when self pollinated).
The F. tibetica seems like a good alternative though.
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On failing to get it from USDA, I actually managed to contact the scientist who developed the tetraploid vesca, and he had seed left over and was willing to share. But then āthis happened and that happenedāā¦ I had dropped off communication before I got to acquire them. Iām thinking maybe Iāll try again, message him tomorrow and see if heās still able and willing.
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Maybe if he knew the USDA lost his tetraploid heād re-supply them too.
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Self compatible rubus specatabilis clones exist. Rubus idaeus in the wild was also originally self incompatible. All you need is one gene to fix it and the gene for self fertility is quite dominant.
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My R. spectabilis (Olympic Double) should be self-fertile. I planted it this year and got one flower on it so I have no first-hand experience with it yet.
EDIT: if hawaiiensis is closely related, it would also be a potentially interesting one to try to cross with arctics. However, I think the bland taste of spectabilis could be an advantage. The nectar raspberry breeding ended up with raspberry flavor being dominant over arctic flavor.
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I have an interesting thought. Many of the species within the subgenus Idaeobatus readily hybridize and produce fertile offspring. Iāve been reading up on Rubus illecebrosus which is also a member of this subgenus. Aside from just looking cool, each composite fruit is made up of a VERY large number of drupelets. If this trait was combined with the larger size of individual drupelets from a typical red raspberry the resulting progeny could make verrrrrry large fruits.
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I had that idea a few years ago but gave up on it due to their rather distant genetic relationship. If we are to believe the graph up above posted by Staalmannen theyāre not very closely related at all.
I think I read somewhere that they do cross to some extent but I couldnāt find any info beyond that and thought they would have bred with that species already if it was that easy. They tried a similar thing using rubus sumatranus but couldnāt get anything past the initial f1. Again Iām not saying it wonāt work but thereās no literature on the subject.
If itās just the number of drupelets youāre after it would be easier to use an existing hybrid like this autumn raspberry
I might still have it around but it hasnāt fruited yet so Iām not quite sure.
I donāt know what species they used for this one but they always seem to be hybrids of 6 or more species already. The number of drupelets, the size, firmness, the number of fruiting laterals and berries are all introgressed from different species. Theyāre losing the raspberry taste thoughā¦
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Theyāve suggested dividing the idaeobatus group into three or four distinct groups.They used to go by morphology alone before we had dna data.
Interestingly rubus illecebrosus seems very closely related to rubus rosifolius, which does hybridize with rubus hawaiensis in the wild. The hybrids though are reported to be sterile. I have balloonberries growing with arctic raspberries in a raised bed. Who knows if that could workā¦
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