Author Topic: Strawberry Species / Hybrids  (Read 496 times)

Garrett Schantz

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Strawberry Species / Hybrids
« on: 2021-06-09, 02:21:20 AM »
Figured I would make a thread here about strawberries, not seeing anything about them on the forum - hoping to change that.

Right now I have:

F. virginiana ?: Type grown from seed, spread around in woods from runners. Could be something else, the original plants "died", Musk strawberries and vesca types were in that group. Flowers are quite small, leaves resemble F. virginiana more than modern strawberries.

F. virginiana Port Huron: Type from Oikos, supposedly resistant to foliar diseases. Forms runners.

F. chiloensis Coastal Strawberry: Type from Native Foods Nursery. Red fruit, forms some runners, glossy leaves, compact.

I have some newer Pink / Red flowered types, will probably replace them with Lipstick and Pink Panda to avoid any potential Plant Patent issues.


I have seeds of Wild Form F. vesca and F. moschata in the fridge right now. Bought them from Edenwilds. My old plants died from shock when I tried digging them up and moving them.

Ordered three white strawberry "plants/crown" - probably plants at this point. The seller on Etsy is frugalfranks. The seller is pretty close to my area - which is nice on shipping and general acclimation. The variety is listed as "Alpine White Strawberry". Fruits appear to be sort of round, "normal" looking seeds - not red like pineberries which are Fragaria × ananassa. There are also white F. chiloensis types. These appear to be F. vesca - hard to find actual white vesca varieties.

Also ordered Potentilla indica / Duchesnea indica plants from Fires Creek Farm. I will be using these for pollen, keeping them in a controlled area.

I also have some other sort of Potentilla growing in the yard, moved a plant into a controlled area. Unsure if I even want to attempt crosses with it.

Prairiemoon sells a few Fragaria relatives as well.


Some fun colors in strawberry species:
https://www.researchgate.net/figure/Fruits-of-seven-Fragaria-species-and-two-forms-native-to-Tibet-aF-nilgerrensis-bF_fig2_318356513

Some mention of cold resistance in strawberries, along with breeding with different ploidy counts.
https://www.sciencedirect.com/science/article/abs/pii/S0304423818300980

Ploidy count of some different species - mention of SC / SI types as well.
https://bsapubs.onlinelibrary.wiley.com/doi/10.3732/ajb.1400140

And of course some Fragaria x Potentilla interspecific breeding. Potentilla indica and F. vesca apparently had sub-lethal traits in their offspring. This could be due to differing ploidy counts along with being in a seperate genus. Vesca is 2x while Indica is 8x. Fragaria × ananassa(8x) x F. vesca(2x) are often sterile or have a low fertility, not surprised that it didn't work too well.
https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1601-5223.1971.tb02372.x


More mention of interspecific breeding. Bit of success with P. indica and F.×ananassa when indica is used as the female. Good bit of barriers are present.
https://link.springer.com/article/10.1023/B:EUPH.0000030665.95757.76


Interesting that Potentilla species don't seem to be good as female donors in 2x crosses - better used for male pollen. 8x crosses seem to be reversed.

I mentioned Fragaria x Rubus possibilities in my Rubus thread - wondering if ploidy would influence male / female usage in this case as well. If I ever attempt that cross with success, it will be in its own thread.




 

ImGrimmer

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Re: Strawberry Species / Hybrids
« Reply #1 on: 2021-06-09, 04:19:42 AM »
Do you know what technique is used to do controlled pollination in strawberries?
I would like to make controlled crosses between different types, (European wild strawberry and cultivated types) but wonder how to prevent self-pollination and do controlled pollination.
So far I have helped myself by planting different varieties in a jumble and watching out for unusual offspring. But it's like a lottery....

Garrett Schantz

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Re: Strawberry Species / Hybrids
« Reply #2 on: 2021-06-09, 11:05:16 PM »
Do you know what technique is used to do controlled pollination in strawberries?
I would like to make controlled crosses between different types, (European wild strawberry and cultivated types) but wonder how to prevent self-pollination and do controlled pollination.
So far I have helped myself by planting different varieties in a jumble and watching out for unusual offspring. But it's like a lottery....

Basically the same technique as tomatoes. Remove the stamens of the female plant that you want pollinated - before the flower opens, use the open flower / pollen of the other variety that you want to use a a parent.

European wild strawberry strawberries are F. vesca, the commonly cultivated types worldwide with large fruits are F. × ananassa. Both of these cross pretty freely, even though they self pollinate and are self compatible, offspring between the two species will probably look pretty similar to one another, probably lowered fruit set.

F. vesca's ploidy is 2x, while F. × ananassa's ploidy is 8x. Their resulting offspring is usually mostly infertile - the F2 generation can segregate into a bunch of different ploidy types if they do manage to set fruit. Some of these ploidy counts can result in lowered fruit set. Runners still allow the hybrids to spread as clones.

Some people use other Fragaria species with different ploidy counts to restore fertility.

Lupineaster on Ebay is offering F. viridis(2x / SI) and F. nilgerrensis(2x SC) - not shipping/offering these seeds to the U.S. it seems like. Plus a permit would be needed to get them here, someone in Canada could buy them and probably send them over here pretty easily though. F. viridis could be crossed into F. vesca in order to make a SI offspring for further breeding - would be nice not having to emasculate flowers.


Having a fragrant / large strawberry would be nice.

Here is a video showing the emasculation process: https://www.youtube.com/watch?v=Fgo83iz76Ow

Garrett Schantz

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Re: Strawberry Species / Hybrids
« Reply #3 on: 2021-06-09, 11:31:48 PM »
Also going to note - the "fragrance" and certain flavors don't appear to be single traits, this can make selecting for them in such hybrids pretty tricky.

ImGrimmer

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Re: Strawberry Species / Hybrids
« Reply #4 on: 2021-06-10, 12:52:58 AM »
yes the underlying technique is always the same, I was rather wondering how to do it with these small obscure flowers.... Strawberries are not as simple in structure as other flowers e.g. citrus flowers. with their large obvious stigmas. I suspect there will be a lot of uncontrolled pollination in strawberries, especially self-pollination because it is so difficult to remove all the anthers.
It must be manageable, but I wonder what is the easiest way to manage it?


Garrett Schantz

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Re: Strawberry Species / Hybrids
« Reply #5 on: 2021-06-10, 01:12:58 AM »
Most crosses are done with the larger flowered types which are F. × ananassa, pretty sure they use pollen from the small wild types. Surgical tweezers can cut flowers and other parts easily.

The female / male organs are easily identifiable for me at least. The large yellow portion on strawberries are the female organ - its quite large, the little strings are the male organ. Everything  except for the pistil can be removed, removing the petals and everything else is easier than searching for the male organs to remove.

Johann Kuntz

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Re: Strawberry Species / Hybrids
« Reply #6 on: 2021-06-10, 03:33:10 AM »
This year I had the amazing luck of finding Fragaria vesca subsp. bracteata forma helleri which is a rare form of the woodland strawberry with a pale pink color to the flower petals.  To my knowledge this is the only pink flowered strawberry that is not derived from intergeneric hybridization (I could be wrong about that).  This is a diploid and of the type that would flower just once per year.  It also produces runners.

I've been contemplating what I could do with it in terms of breeding and I think I'd like to cross it with Fragaria vesca subsp. vesca forma semperflorens which is the cultivated alpine strawberry (also diploid) as this form has been selected for a day neutral flowering habit.  It would be super cool to get an alpine strawberry with pink flowers and continuous bloom during the growing season. 

I suspect that the pink flower petals of forma helleri must be recessive which would explain why it's so rare within the subsp. bracteata population.  This would likely mean that the F1's would be exclusively white flowered and a small percentage of the F2's could express the pink coloration.  I'm not sure if the day neutral flowering trait is dominant or recessive, but either way it would take a minimum of two generations to even have hope for the right genetic combinations to produce the desired result.

Note: Image attached of Fragaria vesca subsp. bracteata forma helleri flowers, but the photo quality is really poor as I had taken it on my broken phone.  Next year when it blooms again I'll be getting better pictures.  This thing was growing in full shade too, so I expect the pink could be more saturated if it received a bit of direct sunshine.

Diane Whitehead

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Re: Strawberry Species / Hybrids
« Reply #7 on: 2021-06-10, 08:55:09 AM »

Fragaria chiloensis is dioecious which makes crossing easier.
Victoria, British Columbia, Canada
cool mediterranean climate  warm dry summers, mild wet winters,  70 cm rain,   sandy soil

Garrett Schantz

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Re: Strawberry Species / Hybrids
« Reply #8 on: 2021-06-10, 01:09:49 PM »
The gendering of strawberries - an interesting topic on its own.

https://www.biology.pitt.edu/sites/default/files/facilities-images/3311.pdf
F. virginiana for example has hermaphrodite and female plants, usually in the same populations. It is thought that the hermaphrodite plants produce a lot more pollen and flowers, which in turn attracts beetles which make nests in the flowers. The female plants probably aren't heavily targeted because they produce less food for insects. Believe this is called "Gynodioecy ". A lot of other species of strawberry have this system as well.

F. chiloensis is considered Subdioecious in a lot of studies - this is because there are a few hermaphrodite types. Subdioecious basically means: Having most, but not all, individuals dioecious. I am not aware of any F. chiloensis varieties/accessions that are hermaphrodites, granted there aren't many types available to begin with.



This year I had the amazing luck of finding Fragaria vesca subsp. bracteata forma helleri which is a rare form of the woodland strawberry with a pale pink color to the flower petals.  To my knowledge this is the only pink flowered strawberry that is not derived from intergeneric hybridization (I could be wrong about that).  This is a diploid and of the type that would flower just once per year.  It also produces runners.

I've been contemplating what I could do with it in terms of breeding and I think I'd like to cross it with Fragaria vesca subsp. vesca forma semperflorens which is the cultivated alpine strawberry (also diploid) as this form has been selected for a day neutral flowering habit.  It would be super cool to get an alpine strawberry with pink flowers and continuous bloom during the growing season. 

I suspect that the pink flower petals of forma helleri must be recessive which would explain why it's so rare within the subsp. bracteata population.  This would likely mean that the F1's would be exclusively white flowered and a small percentage of the F2's could express the pink coloration.  I'm not sure if the day neutral flowering trait is dominant or recessive, but either way it would take a minimum of two generations to even have hope for the right genetic combinations to produce the desired result.

Note: Image attached of Fragaria vesca subsp. bracteata forma helleri flowers, but the photo quality is really poor as I had taken it on my broken phone.  Next year when it blooms again I'll be getting better pictures.  This thing was growing in full shade too, so I expect the pink could be more saturated if it received a bit of direct sunshine.

Does this type form runners? Being able to move a few plants elsewhere would probably be nice and convenient. A lot of the commercial or "wild forms" of F. vesca are old cultivars, same wild accessions - mostly always the types from Europe, although there are North American types. Sheffields has a wild form collected in Holland which could be diverse.


Another note - the Potentilla species that I found and moved into an area where it wouldn't be disturbed - seems to be native! (Potentilla canadensis)  So I don't have to worry about it spreading, becoming a nuisance due to my sparing it.
 A negative would be something that was mentioned on Wikipedia: The Natchez give the plant as a drug for those believed to be bewitched.. This makes me believe that there is some kind of drug-like compound found in the plant. Rather not introduce anything bad into strawberries - though I do want a yellow flower for breeding purposes, say a yellow x pink/red flowered strawberry. I could use Potentilla indica for this purpose, it is noted as edible - though tasteless.

Some other Potentilla species of interest, mainly for flowers or growth types:

Potentilla indica - Edible fruit - though tasteless, yellow flowers
Potentilla atrosanguinea - Red Flowers
Potentilla thurberi - Pink / Red Flowers
Potentilla longifolia - Large / long leaves
Potentilla villosa - Wooly / Hairy leaves, could keep pests away

Alchemilla species are apparently very closely related to the Potentilla genus. This could mean that it is also related to Fragaria, Potentilla's other close relative. Suppose I will mention notable Alchemilla species as well.

Alchemilla erythropoda - Water repellant, dwarf
Alchemilla vulgaris - Water repellant

These both also have a good number of flowers, disease resistances.

Of course these could all have widely differing ploidy counts, toxicities.

« Last Edit: 2021-06-10, 01:14:21 PM by Garrett Schantz »

Steph S

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Re: Strawberry Species / Hybrids
« Reply #9 on: 2021-06-11, 11:26:22 AM »
Fascinating subject, I had no idea that Potentilla are so closely related although the wild ones are very similar to wild strawberry in their leaf shape.
There's nothing terribly noxious in Potentilla that I know of, so I wouldn't worry about creating anything poisonous but taste may be a different story.    Afaik besides being rich in tannins the main activity of the potentillas is adaptogenic and anti-inflammatory.  As such they were added to remedies of all kinds to 'enhance' other medicines.

I have a wild strawberry and a garden escape type that are really abundant in my garden.  The wild strawberry is something I considered a good "weed" to have and selectively let them spread in my early days here.  The garden patch I gave up on decades ago - robins ate most of them, and if I kept the robins out, slugs ate the rest.  The garden escapes turned up in another area, I assume from seeds spread by the birds that ate them.  Since I started growing garlic in raised beds, the 'cultivated' strawberry types have really flourished around the edges of the beds, and I like having them there to soak up moisture and nutrients leaching away, so I pull the other weeds and let them stay.  They've spread throughout.  Probably due to the robins that patrol my garlic rows.   The wild strawberry starts to bloom a couple of days earlier, but there's lots of overlap for crosses to occur.  I notice in the past couple of years that somebody's honeybees are foraging here, and they are on both types of strawberry flower.  The bumblebees which are queen of the garden here don't show any interest in the strawberry.  So perhaps something will turn up in the future, if these are species that can be crossed.

The wild strawberry has a narrower leaf shape, besides being much smaller.  I'll have a look for intermediate leaf types.  One thing I'm happy to report, no sign of damage on either after yesterday's frost and 2 cm of snow (other than being wet and bent down).   I've read that the center of the flower turns black when frost damaged.

I have Potentillas of various types in the garden too, both domestic and wild.  No sign that they readily crossed with strawberries in the wild.


Garrett Schantz

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Re: Strawberry Species / Hybrids
« Reply #10 on: 2021-06-11, 02:41:58 PM »
Ploidy count probably differs a bit between the Potentilla species, which could cause issues with natural crosses.

A lot of the artificial crosses with the species of the same ploidy counts usually have the female organ turn black, and fall off. Which means strawberries usually reject the male pollen of Potentilla species.

The garden strawberry, (F x anassa) is a hermaphrodite, with a few exceptions. If there is your wild strawberry's pollen, along with its own pollen, the strawberry will probably reject the Potentilla  pollen species very quickly.

Probably the same thing the other way around.

I'm assuming that your wild strawberry is F. virginiana, the species prefers full sun. It also has longer / narrower, leaves than the garden strawberry. They should both have the same ploidy count, F. virginiana was one of the parents of the garden strawberry - crosses with it may not be very noticeable.

Steph S

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Re: Strawberry Species / Hybrids
« Reply #11 on: 2021-06-11, 03:02:39 PM »
Yes, I went out and had a closer look at the leaves and googled up virginiana and vesca leaf differences - ultimately I see no sign of vesca, and the difference between the larger berried garden type leaf and the wild virginiana is subtle - would be hard to notice what comes in between the really much smaller middle tooth of the wild leaf and the moderately smaller tip tooth on the garden variety.  They may well have crossed along the way, but I have no way of telling for sure.  There seems a fair bit of leaf shape variation on both the wild and the garden types.

At least I can be pleased that both seem pretty tolerant of cold.

Garrett Schantz

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Re: Strawberry Species / Hybrids
« Reply #12 on: 2021-06-11, 03:27:06 PM »
Yeah leaves aren't the best way to differentiate the species. Vesca should be mostly red on the inside, virginiana is mostly white I I remember correctly.

Steph S

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Re: Strawberry Species / Hybrids
« Reply #13 on: 2021-06-11, 07:48:51 PM »
These are from last year - they look like they might be white inside.   The wild ones here are tiny - like the size of a small pea. 

Johann Kuntz

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Re: Strawberry Species / Hybrids
« Reply #14 on: 2021-06-11, 08:11:16 PM »
Does this type form runners? Being able to move a few plants elsewhere would probably be nice and convenient. A lot of the commercial or "wild forms" of F. vesca are old cultivars, same wild accessions - mostly always the types from Europe, although there are North American types. Sheffields has a wild form collected in Holland which could be diverse.

Yes, the pink flowered form I found produces very long runners.  I'm working on increasing it right now.  I'm in contact with a representative from the USDA as well and will be sending them seeds.  I heard from a friend in the know that experts had been questioning whether this type really even existed on account of such limited documentation and lack of found specimens to confirm the type (till now).  Fingers crossed that this is the real deal and that the pink expresses from year to year and was not simply the result of some environmental stress (the plant seemed healthy and unstressed though).