Strawberry Raspberry Hybrid - other plants

I wrote several previous posts on attempting to create true intergeneric strawberry x raspberry hybrids.  I also wrote a post on how while intergeneric hybrids are sometimes possible and all signs point to my attempt being successful I am not certain if I succeeded.  I can't be certain that it is a hybrid unless the plant is tested genetically.  I contacted a genetics lab before Christmas, had a bit of email exchange with them, but they are yet to tell me a price to have my plant tested. 

Over summer my original strawberry raspberry hybrid plant suffered badly.  It does not look good and hopefully it survives winter.  If this plant does survive there is a good chance it will grow and fruit again in spring.

As well as my first plant I had a lot of seed left over from that first attempt, so I planted more of this seed and ended up with a few more plants. Some are much like the original attempt, others are a bit different.  The differences are rather interesting.

Yellow white berries and elongated petiolules

Again there was a low germination rate, lots of albinism, and a lot of mysterious early seedling deaths.  Most of the plants display the same sorts of morphological oddities as the first hybrid.  These have taken over ten months to flower, as opposed to the five months of the strawberry parent.  The flowers tend to be irregular and inconsistent.  Leaf shape is variable and usually displays greatly elongated petiolules which is uncharacteristic for the strawberry parent species.

All of this suggests that they may be true hybrids.  To be clear, I can not be certain unless they are genetically tested.

Six petals and a stamen in the wrong place

They all look much like strawberry plants.  Most produce red berries much like the initial hybrid.  One thing that surprised me is some of them produce yellow/white fruit.  Which is remarkable considering that the strawberry parent has red fruit.

I have never had a red fruited strawberry produce a yellow or white fruited seedling, which indicates that red is probably dominant and the parent is likely homozygous for red fruiting genes.  If the parent plants were heterozygous for the yellow/white gene I would have seen a lot of other yellow fruited plants before now.

Strawberry x raspberry hybrid can be quit lump

One plant even produces light coloured berries that are a little bit pink!  Unfortunately there were very few berries.  I will have to take more pictures of this in spring when they start producing fruit again.  As they are flowering in cold weather not all of the flowers are setting fruit. 

I left the berries in the pictures below to over ripen to see if they would turn more red.  They stayed pink no matter how long I left them on the plant.  I left one to the point of rotting, and it still stayed pink and did not turn red.  Considering the parent strawberry has only ever produced red fruited seedlings this pink fruited plant came as quite a surprise.

I am quite fond of the pink berry plant.  These produced rather pretty pink berries that smell nice and taste nicely sweet, so I hope they turn out to be productive in warmer weather and I can somehow divide it.  

Pink strawberry raspberry hybrid

Only time till tell which of these plants, if any, are worth keeping. 

I also planted some seeds from the original hybrid and currently have three F2 plants that I am growing out.  So far they are about ten months old and none of them have flowered and none have produced any runners.  I will be interested to see what they turn into.

Extra petals, flowers subtended by a leaf

Only 5 petals on this one, this plant never sets fruit

Yellow/white strawberry raspberry hybrid

Unlike the original hybrid or the pink fruited plant, the plant that is producing yellow or white berries is a bit bland, they also aren't very fragrant.  This may be due to the berries ripening in cooler weather.  In spring when it starts to fruit again hopefully they taste a bit nicer.

Similar to the original hybrid, these yellow/white ones have achenes on the outside, and can be a bit lumpy and bumpy.  Even though the strawberry parent produces a huge number of runners from a young age this yellow fruiting one has not produces any runners as yet.  It will be interesting to see what happens.

I sent samples of these plants to the CSIRO who tested them and determined that they are true hybrids.  The results can be seen here.

While I don't sell these, I do sell some strawberry plants when I have enough to spare.  If you are interested they are listed on my for sale page.

strawberry raspberry hybrid plants

It is time for another update on my strawberry raspberry hybrid. The plant still looks like a strawberry plant. While I took every precaution to prevent stray pollen I can’t ever be truly certain it is a hybrid unless it is independently tested by a lab, I will provide an update on that later in this post.

While the strawberry parent grows runners from a few months old this plant has never produced any runners.  I unsuccessfully attempted to divide the crown in early spring, for a while it looked promising has since died.  Unfortunately this means that all my eggs are in one basket.  I find this rather stressful.  I do have some other plants, but I really like this first one.

Note the greatly elongated petiolules and bumpy berry

The plant itself is still producing flowers that are subtended by a leaf, and they often have extra petals.  It is still producing leaves which usually have greatly elongated petiolules and the leaflets are sometimes oddly shaped.

It fruited a few weeks earlier in spring than the strawberry parent, and it produces more flower stalks and more flowers per stalk than the strawberry parent, making it a productive plant.  The strawberry parent produces up to 8 flowers per stalk with 5 to 6 being average while the hybrid is averaging 10 flowers per stalk.

Lumpy hybrid berry

The first few berries produced in spring tasted horrible, very sour, and not fragrant.  The first berries also looked different to last year, they were rounder and had very deeply set achenes.  As the season has progressed they started getting longer and tasting better much nicer like the previous year.  Most of the berries have all of the achenes on the outside just like a strawberry.

Three of the berries had achenes on the outside like a strawberry but also contained a small number of seeds internally within the flesh like a raspberry.  I am not sure why this was happening, it may be a genetic thing or may be a result of insect damage?  I have not taken a photo of this as it happens so infrequently.

In spring the plant was considerably larger than any of the parent strawberry species.  The petioles are much longer and thicker, while the leaflets are considerably longer and wider.  Petiolules are virtually absent in the parent species, but are often elongated in this hybrid.  Leaf size varies with the season so I try to compare it to the strawberry parent, and so far it is much larger.  I had a lot of plants of the parent species, and none of them was even close in size to the hybrid. 

The berries are white inside

I collected seed from the hybrid as well as from the parent strawberry.  It was not until I had two little bags of seed side by side that I noticed the hybrid achenes are larger than the strawberry achenes.  They weren’t all larger, some were the same size, but on average they were noticeably larger.

I had started to wonder if perhaps this plant was not a hybrid but was a result of spontaneous polyploidy.  Polyploidy can cause larger leaves and fruit, it can cause more vigorous growth and more flowering, it can cause odd flower structures and other morphological abnormalities, often polyploids taste comparatively insipid but sometimes they can taste good, and it could explain all of the difference I have seen.  I wanted to see if it was polyploid.  I took a sample of pollen from this plant as well as both parent species and observed them under a microscope.  Polyploid pollen is often larger than diploid pollen.  Surprisingly they were indistinguishable and none of the pollen was noticeably different.

I emasculated and bagged some flowers and attempted to pollinate them by hand.  I missed blackberry season last year and attempted to pollinate some with youngberry pollen and others with raspberry pollen.  Flowers that were not pollinated or were pollinated with youngberry aborted early, indicating that fruit set is caused by effective pollination and not through apomixis.

I want to try youngberry pollen or any of the blackberry aggregate this year as I have a feeling it may be possible.  Some of the raspberry pollinated flowers aborted late, and some appear to have been successful and were forming fruit until they were eaten by something in my garden.  If these were a hybrid then these seeds would carry three quarter raspberry genes and I would love to have seen what the resultant seedlings looked like.

Most have weird bumps and lumps for some reason

So far, everything indicates that this probably is a true intergeneric strawberry raspberry hybrid, but I can’t be certain.  I contacted a lab to get this plant tested to determine if it is a true hybrid.

After several attempts and being told that my request had been passed on and must have fallen through the cracks the lab eventually replied.  They said this specific testing has never been conducted, but it may be possible. They also warned me that as this type of analysis has not previously been performed it is unknown if there will be enough variation between the parental strains to determine if the hybrid is a true hybrid.  A brief literature search indicates that both parent species have been extensively studied, meaning that there is a high chance of this test being conclusive.

I provided them with further details, twice, and am still waiting for them to reply with pricing and further details.  Hopefully this is within budget and they are able to conclusively determine if this is a hybrid or just an interesting mutant strawberry.  I have no idea what a test like this would cost but I really want to know for sure if this is a mutant or is the first ever fruiting strawberry raspberry hybrid.  Who knows, I may turn to some form of crowd funding in order to cover the cost.

Below are some pictures of the berries, most have weird bumps or lumps, a small number look like the strawberry parent.  I have some other exciting news about strawberry raspberry hybrids, but that will wait for another blog post.

Edit to add: I sent samples of these plants to the CSIRO who tested them and determined that they are true intergeneric strawberry raspberry hybrids.  The results can be seen here.