Redomestication of Cold-Resistant Bananas

[Lauta_hibrid]

Redomestication of Cold-Resistant Bananas

To understand the domestication of bananas, we begin with two species that have an impact on today's edible varieties: Musa acuminata and Musa balbidiana.
About 7,000 years ago in New Zealand, a mutation appeared in some Musa acuminata ssp. bankssi plants, which produced fruit and pulp without needing to be pollinated (parthenocarpic fruit). This characteristic was passed from one plant to another, from this subspecies to others, and even to other species through hybridization, generating enormous genetic complexity in modern cultivars.
Sterility was an independent event, since if pollen from wild varieties was available, these cultivars would continue to produce seeds. One of the events that reinforce sterility is the triploidy mutation; therefore, most current cultivars are triploid.
Independently, further north, in colder regions like India, Musa balbisina was independently domesticated, enlarging the fruit and producing softer, often sterile seeds, thus enabling the fruit to be used in a variety of ways.
When the "cultivable" Musa acuminata was introduced alongside the balbisiana, they hybridized, generating AB plants, thus transferring parthenocarpy to this second species.
There were some plants that did not fit well with the classification and appeared to be fully parthenocarpic Musa balbisiana genetically, designated by some authors as BBB rather than ABB. Through recent genetic studies, it has been possible to elucidate that ABB cultivars may have a more complex history and appear to have originated from AB cultivars.
The ABs were backcrossed until plants with almost complete Balbisiana genetics were obtained, but they retained the Musa acuminata genes that generate parthenocarpy. A cross with Balbisiana was then carried out, giving rise to different lines of ABB cultivars. For this reason, some ABBs appear as BBB in analysis.
THIS TELLS US THAT WE CAN BRING PARTHENOCARPY TO DIFFERENT SPECIES OF COLD-RESISTANT BANANA, GENERATING ALMOST COMPLETELY PURE GENETICS, BUT WITH THE CORRECT GENES TO PRODUCE EDIBLE FRUIT.
THE PROJECT:
Taking these factors into account, we can develop strategies to accelerate this process, but using Musas with cold resistance and aptitude for cultivation in cold climates.
To begin, we can directly use the most cold-resistant and parthenocarpic cultivar: Bluggoe ABB.
Benefit: It is already cold-hardy, producing in my zone 9, and its height is 2.5 to 3 m at the time of fruit production. It tastes good when ripe and cooked.
Regarding its useful residual fertility: it is occasionally capable of developing viable pollen and easily forming seeds (when crossing it with Musa ornata, I obtained 1 seed for every 3 fruits).
Its seeds tend to have poor fertility, but if they sprout, they usually have diploid and "triploid" genetics, very rarely tetraploids.

Optimally cold-resistant parent:
Musa velutina:
Dwarf cultivar (flowers at 1.6 m), short seed-to-fruit cycle (18 months), possible to grow in a pot for winter protection, low light requirements (although it improves in the sun). Easy hybridization with acuminata, cold-hardy (USDA 7b).

So, what do you think of my project? What do you think? If anyone else wants to develop their own, I can pass on the information I've gathered over the years.

[BP]

I think that was an interesting read and your project is super cool! That Musa velutina is very pretty I'd love to grow it

[SoCal2warm]

Parthenocarpy is one strategy to have a seedless banana.
Triploid chromosome number is another. (Plenty of discussion about that does exist in the citrus section of this forum)

[Lauta_hibrid]

Parthenocarpy is one strategy to have a seedless banana.
Triploid chromosome number is another. (Plenty of discussion about that does exist in the citrus section of this forum)

I don't know which discussion is causing problems with this issue. Fortunately, in this case, unusual or difficult experiments aren't necessary to induce triploids; cultivable varieties are already capable of doing it on their own. There's another strategy that seems easier, which is to use a tetraploid banana. In experiences recorded with Fhia 21 (French-type banana from the AAAB group), it produced good pollen, and when it pollinated a fertile Musa acuminata, abundant fertile seeds were produced, yielding plants of diverse ploidy, many triploids, and over 90% parthenocarpic. Unfortunately, I don't have Fhia 21, but in the future, I'll be able to use Fhia 01, which I do have.

Improving Crossing Efficiency by Exploiting the Genetic Potential of Allotetraploid Cooking Bananas:

[SoCal2warm]

You may wish to try to use Musa sikkimensis in your hybrids.

[Lauta_hibrid]

I don't know which is more resistant, M. basjoo, M. velutina, or M. sikimensis... Have you ever compared them? My project is based on what I have here in my country. If anyone wants to send me seeds, they're welcome. I'll see if I can get my hands on some M. basjoo; I think a collector here has some. But you also have to keep in mind that flowering must be rapid, and velutina already gives me that characteristic.

[a_Vivaldi]

I don't know which is more resistant, M. basjoo, M. velutina, or M. sikimensis... Have you ever compared them? My project is based on what I have here in my country. If anyone wants to send me seeds, they're welcome. I'll see if I can get my hands on some M. basjoo; I think a collector here has some. But you also have to keep in mind that flowering must be rapid, and velutina already gives me that characteristic.

Musa basjoo is, by far, the most cold hardy if that's what you are asking. But it does not usually flower and fruit in colder zones.

M. velutina is much less hardy, but it can flower and fruit in colder, shorter seasons than basjoo normally can, and is much more reliable at fruiting and ripening. I think M. sikimensis is variable and depends a lot on the cultivar, but regardless it's not as reliable as either of the other two.

M. veluntina is probably the only one that realistically could be bred for producing cold hardy edible banana. But even then it's going to be a lot of work. Odd ploidy could be used for seedlessness, sure, but M. velutina also has the issue that the fruit will split open when ripe which is not a desirable trait.

[David Kipps]

Does M. velutina possess the trait of being able to develop fruit in the absence of pollination?  If you made a triploid version of it, would it grow seedless fruit, or not grow fruit at all?

[a_Vivaldi]

Does M. velutina possess the trait of being able to develop fruit in the absence of pollination?  If you made a triploid version of it, would it grow seedless fruit, or not grow fruit at all?

That I don't know.

It might be the case that you'd actually have to do some really complex breeding to bring over multiple traits from commercial type bananas into hybrids with M. velutina and then somehow try to segregate out the useful traits of both, if that's even possible. Or maybe M. velutina has most of the traits already and just needs a little tweak here and there and a triploid version for seedlessness, dunno. I used to lurk over at bananas.org and I roughly recall the species being discussed over there, but I don't remember any of the details.

I briefly considered trying to research and start a M. velutina breeding project, but I shelved the idea to focus on citrus and rubus, and because my wife thinks banana plants are gaudy looking and ugly haha

[vnomonee]

I discussed this a bit with Lauta_hybrid, but my idea was just to improve Velutina. Mass planting seeds and selecting the root hardy survivors as well as those that will flower and ripen the fruit before frost. It is borderline hardy in zone 7a, though I've seen a youtube video where one was grown in a zone 6b (maybe a good microclimate).

I bought seeds but nothing sprouted. My first attempt so I will try again. I think the seeds were too old as when I nicked one with a nail clipper to break the seed coat the inside released a white dust lol. So def too old.

I could reserve a space and mass plant some seeds next season, will just need a source.

[Lauta_hibrid]

I think I mentioned it at the beginning, Musa acuminata is the only one that develops parthenocarpy, so if you make another triploid species it will not produce edible fruit (it is not parthenocarpy). That's why all edible plants in Eumusa are AB, AAB or ABB, they always have A (acuminata) in their genetics. My idea is to cross the hardiest of the edible plants (ABB bluggoe) to pass parthenocarpy and cold resistance to Musa velutina (VV). To achieve something with AV, ABV or ABBV genetics. If it comes out AV, it may lose sterility, but it could be used in more complex crosses or in more generations to try to prevent it from setting seeds. The other option is to use AV (from the first cross) and cross back to Velutian to make something like Vª V, where the first V with a small ª represents that the chromosome was mixed and has genes from the A chromosome, thus transferring the parthenocarpy sequence which would be composed of only 3 regulatory genes. This would still be a more complex task, but for now it would be a success if I managed to get a triploid ABV since it would produce seedless fruit in the first generation. Let's keep in mind the experience gained using Fhia 21 (AAAB) pollen with a wild AA. The majority were triploid and produced seedless fruit, which shows us that it can be achieved in one generation and only take a few years. If anyone is from a place where Fhia 21 or another tetraploid type Bluggoe from Fhia can be obtained, I advise you to use it.

[Lauta_hibrid]

Here are the velutina genetic hybrids I could find. There's also an AV hybrid to give you an idea of ​​what can happen when crossing edible bananas. Although Musa acuminata zebrina doesn't exhibit parthenocarpy (it doesn't produce fruit with pulp or seeds). Only Musa acuminata subspecies banksii and its descendants (edible bananas and plantains) have achieved parthenocarpy. If anyone has sikimensis seeds they'd like to share for my projects, or another resistant banana, they'd be welcome. And if anyone travels from Argentina to the US, let me know so I can give them seeds.

[JSea]

Musa velutina is not cold hardy at all in my experience. It seems to be a complete myth. I would rate it as similar cold tolerance to Dwarf Cavendish and possibly worse (!). The fact that I have never killed a Dwarf Cavendish (they always recover despite major damage), and I have killed multiple Musa velutina, possibly even points to it being less cold tolerant than Dwarf Cavendish.

What is cold hardy though, is Musa mannii. This is quite cold hardy, at least as much as Musa acuminata, and probably closer to Musa sikkimensis. It has pretty much all the positive traits of Musa velutina other than the nice pink fruit.

Musa yunnanensis also seems to have similar cold tolerance as Musa sikkimensis.

There are also some BBB bananas out there as well, although I don't know much about them.

Also New Zealand is definitely not involved in the domestication of the banana, Australia maybe, but probably Papua New Guinea

[vnomonee]

Jsea when you mention major damage are you are you talking about the hardiness of the pseudostem and leaves recovering from cold damage? The hardiness I am interested is at the corm level, which will need to resprout after winter here like the musa basjoo does in the spring after freezing down to ground level.

[JSea]

I'm talking complete defoliation, mild damage to pseudostem for the Dwarf Cavendish.
Musa velutina is completely dead under the same conditions for me, corm included. It's possible this could be related to excess soil moisture rather than cold tolerance, but I think that's unlikely given how well most other Musa cope with wet soils.

And in these same conditions, Musa mannii is able to retain most leaves and even push the odd one out if there's enough fine weather.

[Lauta_hibrid]

For now I have few genetic resources, my other bananas are still missing to give flowers, so I will use these. And about Cavendish, zebrina muse and velutina muse: with the cold my Cavendish dies the pseudotayo, zebra too and velutina muse too... although in hesitation it has remained firm this winter and just the spring is already making flowers. To my experience in my climate velutina has resisted more and gave flower fast, pires corra. A little above my waist it already bloomed. I like that since the short cycle allows that if the pseudo stem is burned that does not harm the recovery and formation of fruit. But I'm very interested in Musa manii, do you have seeds of that variety? My Citrus hybridization project is already in its flowering stage after 6 years of work, so I have to focus on my next project. I also have Musa ornata, that one keeps the pseudo stem in the same conditions, as do Mysore and Bluggoe. Do you have any idea the cold resistance of ornata?
By the way, I was reading a paper that talks about the origin of ABB bananas and their genetic complication in the analyzes. And there they clarify that the BBBs are actually ABB but with a retro crossing with balbisiana, so the analyzes did not make their origin clear. I already suspected it since there was no parthenocarpal balbisiana.

[JSea]

There's from memory a few forms of velutina that exist (e.g. Musa velutina subsp. markkuana), and some of them have possibly hybridized with Musa ornata and similar species before, so cold tolerance can vary somewhat I think.

I don't have seeds of Musa mannii, my 2 plants are not very large yet (I think they are slower growing than Musa velutina, in exchange for the extra cold tolerance). I should have seeds in a few years But also the plants are getting established well now, and I'll repot them any week now and hopefully get a good Summer of growth.
I should also note I was never able to sprout a single Musa velutina despite trying maybe 3-4 times with hundreds of seeds (some straight out of the fruit), but I sprouted Musa mannii twice with two attempts (once with fresh fruit, another time with dry seeds).

Musa ornata I'm not too sure on the cold tolerance of. It does hybridize freely so it may not always be pure and may vary. I wouldn't class it as a cold tolerant banana though I think, not like M. sikkimensis / M. basjoo / M. yunnanensis anyway.

I would be interested to read that paper about the BBB varieties, as I did wonder how it's possible that they existed.

[Lauta_hibrid]

Unraveling the complex story of intergenomic recombination in ABB allotriploid bananas
https://www.biorxiv.org/content/10.1101/830059v1.full

[Lauta_hibrid]

I'm going to show you my latest attempt at crossing Asian hornet (Vespa velutina) with Bluggoe. Luckily, I found a flowering plant in the center of my city. As you can see in the first photo, the stamens were opening, revealing that there was something inside. To properly remove the small amount of pollen found on a stamen, you should gently scrape it with a smooth surface like a knife. The friction lifts the two longitudinal flaps that cover the pollen area, thus recovering some pollen. To be fertile, it must be white, unlike citrus, which is orange-yellow. Its appearance is not powdery. I picked the Asian hornet with the inflorescence still having its first two bracts closed. This is because Asian hornet flowers are hermaphroditic and tend to release pollen before opening, which would ruin our plans. I moved the bracts back and carefully removed the flower petals and stamens. Keep in mind that you should check the stamen by gently pricking it with your fingertips to see if any pollen remains. If pollen is released, the stigma must be removed to avoid contaminating the next flower, as they are very close together. Then I proceeded to check the bluggoe flowers and rubbed them when I saw the stamen still closed by those little sacs (which I don't know the name of). I saw plenty of white pollen, so I pollinated them. From the last three flowers, I removed the stamens, style, and stigma to see if the ovary develops or not; that will tell me if fertilization occurred. The last thing is to cover it with a piece of paper like a hood so that no insect dares to pollinate it. We'll see what happens.
The only bibliography I found on the use of triploid pollen in diploid birds was with Cavendish, and according to the report, all the offspring were diploid. This reflects that their pollen only fertilized when it was haploid, so this could give combinations like: VV x ABB = VA, VB, or VB

Keep in mind that only Acuminata (genome A) has parthenocarpy genes, so many may produce seeds. I hope some are easy to spot (by morphology or height, and are triploid).