Breeding Sweet Potatoes (turning them into a seed grown annual)

[reed]

Raining and raining here so still have lot of plants remaining in the starting beds. Several both still in the ground and potted are developing blooms at a very early stage. I also still have a clone of that original ornamental that blooms so much and is self-compatible. Last several years we have kept it overwinter as a house plant and the woman uses it in her flowerpots on the patio over summer.

I haven't paid much attention to it or saved any seed from it over that time but now I'm getting an idea. I took a couple of cuttings from it, already developing seeds, and put them in small pots so they are easy to move around. I don't really want its pollen distributed in the overall patch because I don't want the non-rooting trait re-introduced back into my strain. I'm thinking when those very early bloomers get going real good, I might take cuttings from them as well and put them somewhere with the old ornamental and see what kind of super blooming ornamental plants might result.

I'm also very intrigued by those apparently miniature plants so I think I might do the same thing with them.  If they continue with this miniature growth habit and assuming they continue to look healthy otherwise I am going to place them together to try get seed specifically from that phenotype.

So, I'll end up with I guess, with four semi-independent breeding efforts. First is seed from the best of the best plants that were cloned from last year which are planted in the big tubs a little distance from the main patch. Second, the super bloomers, semi-isolated from all others, Third, the miniatures also semi-isolated and lastly the main patch of this year's seedlings.

Of course, I have no clue at this point of what kind of root production I'll get from the super bloomers or the miniatures, or even if they will continue this behavior as the season progresses. It will be nice if they do and if any happen to also make quality sized roots it will open up all kinds of fun opportunities for following seasons.

[reed]

Testing some new image software. Well, it worked for this one image but not the others, so I'll go ahead and talk about this particular 2022 seedling. It is unfortunately not blooming yet while I'm guessing about 40% of the others are. I've even harvested a few seeds. I have gotten seeds in July before, but I think this is the earliest ever.

Since so many are already blooming, I'm thinking that after another four weeks or so that I'll go ahead and start culling those that aren't, especially if they have traits I don't like, such as very long vines. As long as blooming starts by mid-August or so there is plenty of time to mature seeds.

Anyway, back to this particular plant. Of course, I don't know yet what kind or color of roots it might have or if it will have storage roots at all. I am however definitely keeping in a group that I'll wait the longest for to bloom.  I really like a compact and bushy growth habit and I have never seen one that has it this extreme. I thought at first maybe it had been clipped by a bird or rabbit, causing it to branch but I've examined it closely and find no evidence of that. Its internodes are an inch apart or even less and its stem at the ground is bigger around than a pencil. I don't know that bushy habit and short internodes has a counterpart underground, (think clump root) but I'm hopeful of that.

There are actually another 1/2 dozen or more very similar plants just not quite as compact and bushy as this one. AND one of them is blooming!

Now to figure out why the other pictures didn't load.

[reed]

Trying the new image software again. Well seems to work better than yesterday but still need to figure out scaling so a person doesn't have to scroll to see the whole picture.  Anyway, this shows one of the potted groups. Those in the big tubs farthest back are grown from clones from the best seedlings in 2020 and 2021. Those to the right are 2022 seedlings. There in the foreground are some that are starting to bloom and one that got snipped by a rabbit and I replanted it. It is another of that phenotype in the previous post, fingers crossed it will regrow enough to see what it turns out to be

[reed]

I'm really pleased so far with how the sweet potatoes are coming along this year. I have about 20 that have already produced a few seeds and happily they are all of the bushy type. I've never had so many all at the same time for a good observation of such things but there is apparently some variation in maturity. That is defining it as getting to the point of starting to bloom, root maturity is of course a whole different thing. 

Along with those 20 that have already produced seeds I'm guessing about 40 more are at the stage of starting to set capsules. Roughly 75% of this second group are also of the bushy type.  A third group is just starting to bloom but I can't tell how many because they are starting to get overgrown and all mixed up, I can't easily tell which branch comes from which plant.

I think, in my climate any that start blooming before the end of August will have time to mature seeds but I'm not sure I want to wait that long before I start culling some. I'm thinking now that I might start that at the beginning of August. I'll start with any that have not bloomed and that have very long vines. I don't like the long vines and think I will try to keep any seed I do get from them separated from the rest. I don't like the long vines mostly because they just take up too much space and it's a pain to try to keep them trellised.

In what I'm calling my production tubs I have clones of plants from the last couple of years (those I'm growing to eat). They are the best of the best in all aspects. Bushy, seedy and productive of nicely sized delicious roots. They are also all blooming and producing seeds and are a little bit isolated from the new plants so will mostly be crossing and backcrossing with each other.

Of course, I won't know for some time what kind of roots the new ones will have. I planted a lot of older seed that may lack the selected adaptation for nice roots so I suspect not more that 1/2 of these new ones will have good roots. Still as many as there are I should have plenty good new ones to add to the clones next year.

That pesky issue of compatibility is still lurking around. I still have that original self-compatible clone that started all of this, and it made the first seeds this year, reconfirming since no others were blooming yet that is indeed self-compatible.

The production plants are much larger and branchier than the new ones, so I could take some cuttings and isolate them individually to see if any of them are also self-compatible.  Even if they are though, I'm not sure what it would prove because I know from the original one that offspring from a self-compatible plant aren't necessarily self-compatible themselves or even compatible at all.

[AndrewB]

The bushy plants probably have shorter nodes and thus would reach flowering stage earlier regardless of any other genes that might code for earlier flowering, so by continuing to select for those you might be on the right track. Maybe short bushy plants are the way to go for temperate and northern climates as well.

[reed]

The bushy plants probably have shorter nodes and thus would reach flowering stage earlier regardless of any other genes that might code for earlier flowering, so by continuing to select for those you might be on the right track. Maybe short bushy plants are the way to go for temperate and northern climates as well.

Yes, they definitely have shorter nodes and I hope to find out this year for sure if that has a counterpart underground, read clump root! If I can get all of that together, compact, bushy, seedy, clump root and short maturity time then they could be grown almost anywhere. Clump root is easier to dig if grown in the ground and takes up less space in a small garden. They might also produce just fine in a pot on the patio, it doesn't even have to be a very large pot.

I sure hope the one pictured alone in the previous post starts blooming soon. Its growth is so compact that assuming it makes nice roots I may keep it to clone even if it doesn't bloom at all.

[Richard Watson]

Looking really good.

[reed]

Well, the sweet potatoes have turned into an overgrown mess, as usual. The ones growing in the ground are an extra-overgrown mess and last night I found capsules that had already shattered and lost the seeds. Overall, I'm guessing I've been collecting seeds from about 25% and another 25% are starting to mature seeds. That leaves about 1/2 that either have just started blooming or have shown no sign of it. The rest of this month through September and probably even into October should yield the bulk of seeds but any that aren't blooming yet at all, or that are blooming but not setting seeds are kind of just in the way at this point.   

I think this weekend I'll go out and find vines with no bloom buds and see if I can track them back to the trunk in the ground and cull them out. I can just completely get rid of the ones in the pots but in the ground, I think I'll probably have to leave the roots so as not to damage those being left to keep making seeds.  That, along with clipping of a lot of extra leaves will make it easier to find and collect the seeds. I'll try to post some before and after pictures of the process.

[reed]

I haven't updated this for a while, been busy with lots of things. Took quite a few pictures and learned some new tings but for now I'm just going to post this little video I made as I was finishing up harvesting this year.
 

One thing I learned for sure is that I'm not very good at making videos. (ERROR! - I meant to say early October, not September.)

[reed]

I've finished up with harvesting and grading my sweet potatoes for the season. I bit off more than I could chew this year with the number of seeds I started and fear I probably ended up wasting some seeds due to not being able to properly care for them all. I ran out of pots and in ground space so quite a few were left terribly overcrowded in the seed beds where they didn't have a chance to fully show what they might have produced. Plus, it was difficult to dig those grown crowded in the ground without separating the vines from the roots, so I don't know which nice roots came from which vine, so I also don't know if a particular nice root came from a nicely seedy vine. And it was hard to collect seeds from the overgrown patches, so I'm sure a lot of seeds were lost. 

Still, I learned some new things. Most importantly perhaps is that finding an individual plant with all of my preferred traits is pretty rare, probably not more than one in a hundred.

On the positive side I collected a nice bunch of seeds, way more than I planted and am still collecting them from the vines that I stuck back in pots after harvesting the big roots. That will go on until frost and I may even bring some of the most preferred ones inside to get still more.

With those added this year and those from prior years, I now have seven or eight plants that do have all of the preferred traits and about twenty more that have all except for the very bushy growth habit. Two or three have very large vines but are so nice otherwise that I am going to keep them to clone anyway. The rest of the nicely rooted and seedy ones are more of a mid-sized vine, not bushy but also not giant.

I've saved about 50 very bushy and seedy plants that did not make roots and am going to try to keep a lot of them alive as house plants. All of my sweet potatoes started from those same original crosses with that first discovered self-compatible, rootless ornamental. Those ended up with offspring that do sometimes make roots, so I figure the genetics for that are still in these plants, even if it didn't show up in this generation. I haven't given up on a super bushy and nicely rooted strain is why I want to keep these for backcrossing.

I think for next year I will try to keep the total number grown to around 200 and pretty much all of them in pots. I what all of the pots to be the same size, I'm thinking 5 gallons and the soil mix to be consistent in all of them. The 200 plants will be as follows:

*50 (elite) cloned from the best of the best grown in semi-isolation. these include those that do have the nice clump roots but not necessarily the bushy top growth habit.
*50 of the (elite) line, grown in close proximity
with
*50 the very bushy and seedy but non rooting line
*50 from new sprouts (will need to plant at least 100 seeds to insure 50 plants) these will also be in semi-isolation to prevent reintroduction of bad traits into the elite lines.

Here is another little video of results from one of the inground patches

 

[Richard Watson]

A lot of red skins, are they the same colour inside also.

[reed]

The ones with red skins can be either white or orange inside. A lighter color skin is usually orange inside and darker color skin usually white. The ones with white skins are always white inside, as far as I've seen so far. Interesting is those with green leaves are almost always orange inside.

I found two yellow inside this year, they are my favorite for flavor but neither had nice size to the roots or many seeds. An all purple one showed up too. That makes maybe five total over the years, and they all have had issues with bugs or rotting in storage, so I didn't even save this one.

[UnicornEmily]

Hey, Reed!  I just want to say that I absolutely love this thread, and it inspired me to finally stop lurking and sign up to the forum, so that I could post this.

The reason this thread has meant so much to me, reading over it obsessively over the past few weeks, is that my goal is very similar: taking a tropical long-season perennial that's usually propagated asexually and breeding it using seeds to work as a short-season annual.

In my case: bananas.  I'll be using a bunch of cold hardy, dwarf wild bananas to try to breed a local landrace.

I'll start my own thread about it, just like you've done, so that other people can follow along, and perhaps find as much joy in it as I have found in your thread about sweet potatoes!

[reed]

Hey, Reed!  I just want to say that I absolutely love this thread, and it inspired me to finally stop lurking and sign up to the forum, so that I could post this.
The reason this thread has meant so much to me, reading over it obsessively over the past few weeks, is that my goal is very similar: taking a tropical long-season perennial that's usually propagated asexually and breeding it using seeds to work as a short-season annual.
In my case: bananas.  I'll be using a bunch of cold hardy, dwarf wild bananas to try to breed a local landrace.
I'll start my own thread about it, just like you've done, so that other people can follow along, and perhaps find as much joy in it as I have found in your thread about sweet potatoes!

Sweet! really looking forward to being able to grow bananas. There is a strain that has been passed around here in my neck of the woods. One fellow has managed to overwinter it in the ground using lots of mulch.  I grew it one year, it got very large and grew some "pups". I think that's the term, but mine all froze out. My niece takes them in her greenhouse and sometimes gets a few little bananas.

Looking forward to following your progress on this.

[UnicornEmily]

Oh, nice!  If it's seedless, it's probably a Dwarf Namwah or Dwarf Orinoco.  My suspicion is Dwarf Orinoco, since that seems to be the most popular seedless banana for cold hardiness.  Dwarf Namwah seems to be the second most popular.

If anyone in your area ends up with extra pups, let me know!  Cold hardy seedless bananas are very welcome in my yard, too.    I have a baby Dwarf Namwah, and I'm hoping it'll survive this winter without protection.  If I get any extra pups next year, I'd be happy to send you one if you'd like it.

My primary landrace goal is cold hardy, tasty seeded bananas, but if I manage to get brand new cold hardy, tasty *seedless* banana . . . well, that's sorta the holy grail of banana breeding!  *grin*  If I ever happen to have a seeded banana and a seedless banana flowering at the same time, I'll definitely try to cross them and see if anything interesting results.

Do you have any sweet potato seeds you wouldn't mind sharing?  I'd be interested in trying to grow some, and I'll probably trial them for drought tolerance.  I'd be happy to send you back seeds next year from anything promising.  I'm very sold on the idea of growing things from seeds instead of constantly cloning them.  Genetic diversity is so much better.