Strawberry x Raspberry hybrid

These plants have been independently tested by CSIRO and confirmed to be hybrids.

Opens the door to breed a lot of new berries.

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The photos and taste test for those that are wondering:

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Those look like alpine strawberries I used to grow.

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Does anyone know what species of strawberry and raspberry they used? And has the full CSIRO report been published? Or did CSIRO confirm they tested it?

They look quite close to strawberry’s morphologicaly…

I don’t know the person who wrote it. And have no reason to doubth they are trutfull.

Still it feels like an unlikely cross. And photoshopping a single graph from a testing report isen’t that hard… Or contaminating a sample can happen to.

However if quince and malus can be crosses… this might also be possible.

To be clear, im not saying the person who did this is lying. And if it truly is a strawberry X rasphberry hybrid thats quite amazing. However the limited “hard” information followed by the donation link, calls out the sceptic in me.

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I know Burbank tried crosses and from what I remember nothing special resulted. Low production sterile pollen etc. I just went and read his account. All looked like strawberries at first. Then they spread underground like raspberries. Also grew canes later in the year. None out of hundreds produced viable seeds or even fruit for that matter The 2nd year he saw a few fruit. But considered the experiment a failure and ended the experiment.

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From what I read Burbank’s hybrids (assuming they existed) were sterile as the parent stock he used has mismatched ploidy levels. Had he used diploids for both parents he may have had better results.

I think @Caesar was attempting to cross raspberry and strawberry, I wonder if he has had any luck?

I’m finding this hybrid very hard to believe, especially on diploid level. Different strawberry species are notoriously difficult to cross with each other, let alone different genera.

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Notwithstanding the author’s own interpretation, the data in the blog post doesn’t tell us anything that proves or disproves the hypothesis that he has created an intergeneric hybrid. To demonstrate that, you need to show that there are genetic components in the F1 population that could only have come from the raspberry pollen parent. The data don’t show that. It does show that CSIRO detected 152 proteins in the F1 material that were present in the raspberry material but not found in the strawberry material, but because this is a proteomics, not a genomics analysis, that could be because of differential gene expression in the analyzed materials masked the presence of genes for those proteins in the strawberry material. Is that likely? Well, the data also show that CSIRO detected 423 proteins in the F1 that were in neither the raspberry or strawberry material, which is very compelling evidence that a good deal of differential gene expression between the samples was present - an F1 offspring can’t have invented genes for that many new proteins that didn’t come from one parent or other. In short, proteomics is the wrong analysis. The author needs a genomic, or at least a chomosome-level, genetic analysis to make his case.

Like @BerryAllen, I’m skeptical of the claim until we see some genetic analysis. There are two ways the claimed hybridization could have occurred. One is pure sexual reproduction, in which the F1 generation has half of it’s chromosomes inherited from the strawberry, and half from the raspberry. This is only possible if the author used a diploid strawberry species. He gives no indication beyond the word “strawberry” what the female parent was, but most strawberries are not diploid. The common domestic strawberry is octoploid.

The other mechanism is through the formation of a polyploid hybrid, in which the F1 gets a complete chromosome set from both parents. Crossing an octoploid strawberry with a diploid raspberry would give a decaploid (2n = 10x = 70) new interspecific cross.

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i am not as knowladagable as id like to be in this field.

But you say it could only happen if a diploid strawberry was used.

I do however know that somtimes a tetraploid crossed with a diploid can yield a triploid. Even if the diploid and tetraploid are different species.

So im not sure you can rule out everything non diploid.
I however also doubt it is truly a hybrid.

https://www.nature.com/articles/s41438-019-0199-2#:~:text=Raspberries%20are%20diploid%20(2n%20%3D%202,hybridize%20to%20produce%20purple%20raspberries.
is intresting though.

It goes above my knowladge “level” but fig 2 is intresting to me.

What I’m seeing in the pictures looks exactly like my alpine raspberries. They tend to have misshapen berries like that if pollination isn’t perfect. So fragaria vesca var semperflowers. That’s a diploid species. I’d love to be wrong, it would be a cool hybrid but I’m just not seeing it. Distantly related species tend to produce highly sterile offspring but these seem to be flowering ok. For example the strawberry species fragaria viridis and fragaria moschata have averaged only 0,1 healthy plants per pollination. Granted they have different ploidy levels but both are strawberries…

Yes, but a triploid produced that way is almost invariably infertile. He’s got an F2 generation, so it’s highly unlikely that that’s what happened here. Such triploidy is in fact an important mechanism for producing seedless cultivars in domesticated plants.

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My suspicion as well.

@oscar

He used Alpine Strawberries. I’ve commented on his blog before, and exchanged some information. While admittedly the berries look like alpines to me, I’d like to err on the side of optimism, and hope that he really was successful in crossing them.

Burbank’s own hybrids developed some tiny drupelets, so I expected that any successful hybrid would fruit more like a Rubus than a Fragaria.

@TurtleWax

I’ve had that project on hiatus for several years, unfortunately, but this is definitely some highly motivating news! I still have some old Alpines, and have more seeds from several alpine varieties in the freezer, but I lost both of my diploid raspberries last year (Rubus rosifolius and R. idaeus “Caroline”), and R. occidentalis “Black Hawk” a few years back; all lost to different types of neglect.

When I first got Caroline, I was specifically looking for a heat-tolerant raspberry (and it delivered! with a few crops of berries over the years). I had heard that raspberries are typically heat-sensitive, to the point of dying in hot climates. Having recently received a viable, sprouted “Mammoth” rootstock only for it to fully die off after a few days in bright shade, I’m fully prepared to believe that they are so heat-sensitive. I’m a bit paranoid now… I really wanted to trial “Joan J.”, because it’s a thornless primocane, but I’m worried about losing it. They’re available on eBay, but nearly $40 for a pair strains my budget a bit, especially since it’s untested here. I tried to order a Caroline because it had worked so well, only to have my order cancelled by the vendor because they didn’t wanna ship to PR. I haven’t gotten another Blackcap yet, but I know that they can handle heat like a champ. I’ve heard of some people in PR having good results with “Autumn Britten” and “Anne”.

I’m gonna try to get one of these heat-tolerant primocane varieties in the coming weeks. If I can get someone willing to ship to me, I’ll give them all huge pots with good soil, and try to get the experiment up and running again. If I can get them and the alpines flowering at similar times again, I’ll use “Mentor Pollination” to ensure success (last time, the isolated raspberry blooms dried up, the strawberry pollen didn’t take). My biggest problem is that I don’t know how to reproductively sterilize the pollen while leaving it chemically active. People mention freezing (but I’m not fully convinced that works), or microwaving the pollen (but there’s no specifics on how to do it, for how long, etc.). Sounds to me like overcooking the pollen would denature it to the point of rendering it chemically inactive and useless.

One last thing I’d change (and taking a page from our Australian friend), is that, unlike my first attempt (which copied Burbank by using Strawberry pollen on Raspberry flowers), I’ll be using Raspberry pollen on Strawberry flowers this time. It just makes a lot of sense to me on several counts. For starters, I’ve had terrible luck germinating any kind of Rubus seeds. They’ve a tough shell, and require stratification (sometimes repeatedly) and benefit from scarification in order to sprout. Even if I can get the pollen to take, there’s no guarantee I could sprout the seeds if they came from a Raspberry. In contrast, germinating strawberries is easy, and much simpler (you can dry-stratify them in the freezer, and sometimes they sprout without it; I’ve had volunteers from fallen fruit from my alpines). Secondly, it’s a pain to harvest pollen from the few & short Strawberry anthers. Raspberries are loaded with long anthers, cutting off enough for a pollination experiment would be a cinch.

I had other plans for my budget, but I’m thinking next week I’ll spend some cash to try to get several raspberry varieties. I’m pumped up for the project now!

On a final count, has anyone thought of trying for a Somatic Hybrid? I have no lab and thus no resources for it, but if I could find a laboratory willing to take on the experiment, that could lead to interesting results. ¿Anyone connected?

Thanks for the answer. So he used alpine. And what rasphberry?
I still have my doubts.

Somatic hybrids can be unstable. And usually don’t breed any further (sterile)
It sounds like an amazing thing, and there have been useful cases. But there are a lot of dead ends and hurdles with somatic hybrids. It’s good to have realistic expectations.
https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/somatic-hybridization

Interesting ideas. My climate is the opposite so raspberries and strawberries do well. I have successfully produced seeds with both species but for best results I’d use a self incompatible (wild) plant as the seed parent. That way I can be sure every developing seed is cross pollinated. I never collect pollen from insect pollinated plants. I just rub the flowers together. A forest strawberry x alpine strawberry gave 100% hybrid seed in my experiment. I usually have a specific trait as a marker. In this case the mother plant grew without suckers but all plants grown from the seeds suckered freely so I knew them to be hybrids.

Raspberry seeds aren’t difficult to sprout btw. You just can’t let them dry out! (It gets more complicated if you do) Plant them directly to moist soil and the cold stratify for up to 4 months and you’ll have lots of seedlings.

I have read about somatic protoplast fusion being successful with strawberry and raspberry, but I don’t know if they produced fruiting plants or just a mass of cells.

I did a quick google and found this:

https://www.ishs.org/ishs-article/842_101

Some more / same links related to the topic. I am a new user - so I can’t post more than two links. Just edit the Living-mudflower blog URL and add the rest of what I put here. Add (dot)html at the end. These have the main process, not all of the links are present here.

/2018/04/strawberry-raspberry-hybrids

/2018/07/strawberry-x-raspberry-hybrid-plant

/2019/02/strawberry-x-raspberry-experiment-update

/2019/02/strawberry-x-raspberry-intergeneric

/2020/07/strawberry-raspberry-hybrid-plants

/2020/09/raspberry-x-strawberry-hybrid-f2-seed

/2021/05/strawberry-raspberry-hybrids-test (This one is the nicest in terms of results - already present here though)

This 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 begin flowering after two years - like the supposed raspberry parent, the supposed offspring between the cross also forms runners like the Fragaria parent. Runners probably produce even more F1 clones. Quite a nice thing for breeding purposes. The plants don’t fruit until 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.

Someone on another site told me that mass spectrometry was used in this case. Also mentioned that they have seen the data and unique peptides in the hybrid that only occur in one of either parent species - granted that can be seen by looking at the charts / graphs.

The strawberry that Burbank used was a Garden Strawberry (Fragaria x anassa), which is an octoploid. The Raspberry that he used was probably a diploid.

Here are a few Potentilla x Fragaria - Octoploid strawberry x Diploid strawberry articles.

The studies / research have shown, there is a lot of infertility and other issues with crosses of different ploidy counts - even in the same genus. Other species mixed together have other issues as well.

Living Mudflower reported sterility issues in the F1. This was with a diploid Strawberry / Raspberry.

This means that Burbank probably got hit with the sterility issues caused from the differing ploidy count, along with mismatched genes.

Raspberries grow on canes, strawberries sort of creep or grow upright as a small plant. Strawberry “fruits” are also different, the seeds are on the outside, a few other differences. Raspberries don’t even really have the same type of “runners” as strawberries, they just root at the tips.

I am assuming that a bunch of raspberry genes were cut out / skipped over during the initial cross. They couldn’t pair up with the strawberry/raspberry genes in the same location. This might also explain sterility issues, as the generations go on the issues should resolve themselves by natural selection. Anything incompatible either doesn’t flower/set seed, or the seeds with incompatibilities just don’t germinate. Doing the cross in the other direction could have a “strawberry” with canes - it could also result in a larger raspberry on a cane. The cross will probably be more difficult in that direction.

Genes within the different sets of chromosomes need to be similar enough to add on, merge with a different parent’s set of chromosomes.

The test wasn’t a full on genetic test - just a mass spectrometry test, this isn’t a good reasoning that it isn’t a definite hybrid. There are intermediate plants, different leaf types are present - not found in either of the parents. New sugars are present, as well as sugars only found in either parent. As I mentioned before - the raspberries canes, among other traits, may have been cut out immediately - probably won’t be seeing those in the future. Different sugars found on certain chromosomes may have lined up just enough to cross over, same with the leaf genes.

The author also grows a large number of different strawberry varieties / species. I’m assuming that a new flavor in strawberries would stand out very quickly.

Quite an interesting matter. I’m planning on making a tasty rubus intergenus hybrid, attempting to keep it as an octoploid or diploid. Either one works, I want to do this with strawberry species as well, the different species are hard to find. Eventually both of the elite types would be mixed to make something even better / more nutritious. Will probably take a long time…

A genetic test with the F1 seeds / plants, along with tests from both parents, would really help in figuring out what exactly happened here.

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. The Raspberry parent was probably “thornless” - I am assuming.

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 a nice source on the blog as well - talks about wheat hybrids - triticale etc.

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 issues, 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.

I’m assuming that it was just sort of a half-half sort of thing. Half of the genes from strawberries - half from the raspberry. Anything incompatible was cut out quickly.

Interfamilial hybrids can be tricky in figuring out how the cross happened.

If I made any errors here, please do point them out to me.