Author Topic: Ipomoea pandurata, aka man root, man of the earth, wild sweet potato  (Read 292 times)

reed

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I'v established a patch of Ipomoea pandurata with intention of attempting an inter-species cross with Ipomoea batatas. Turns out though that Ipomoea pandurata is pretty interesting on it's own so I thought I would give it a thread of it's own in case anyone else works with it and maybe has some experiences to share.

My research into it indicates that it is rather rare, it isn't. I'v found a number of wild specimens. It is also described as being similar in some ways to I batatas specifically in that is self-incompatible, again it isn't. But there is something weird about it. The very large plant closest to my house made lots of seed in 2016, 2017 and 2018 but none this year. All of the other plants I'v located made no seeds in previous years but two have seeds this year. Another interesting thing about the previously seedy one  is that it is way smaller this year.

Couple years ago I managed two seeds that I think were pollinated by pandurata but they did not sprout. Since the plant close by didn't bloom much this year I wasn't able to collect much pollen and I doubt my recent attempts took either.

As far as sprouting the seeds they are pretty easy, just direct sown or in the cold frame. I do think that unlike batatas they benefit from cold stratification but if you keep your seeds frozen that takes care of that anyway. Seeds planted last year (not cold) treated did not sprout but near 100% sprouted this year. Some started in cold frame transplanted easily with no losses and I couldn't  tell a difference between them and the direct sown. I don't know how long it will take a new plant to bloom but suspect it might be a long time so it may take a while till I have the two species growing conveniently close together.

My patch is out by the mail box at the end of the drive where I'm in hopes they will just go wild and grow up into the weeds and trees like the wild ones do. It's too far from the water source and since they are wild I figured they should be tough enough to fend for themselves. By appearances that is not they case, it very hot and dry there and only one has any live leaves left at all.

But another very interesting thing is I had some left overs from the cold frame that were just set out on the ground and in the pot they were started in and they apparently dried up and died weeks ago. I dumped that pot yesterday and found roots about as big around as a sharpie and if they weren't all curled up would be probably a foot or more long. They are funny looking each one starts out a little bigger just under the stem, goes down three or four inches and  forks like legs. Maybe that's why their called man roots. They were easy to peel, just scraped it off with thumb nail. Taste, raw was largely absent but with a hint of sweet. In any case I can now say I'v eaten wild sweet potatoes. The ones in the ground grew much much larger so I'm imaging they also have much larger roots, I think I will just leave them be though and maybe dig a couple next year. It's encouraging I think that the big roots are directly under the central stem so you don't have to dig a crater to find them.

I put the dormant, rather than dead roots, they each have little bud or two on top, in a shallow pit with a little water and  dry leaves on top to see if they keep over winter that way.

I'm wondering as a food crop if a person might grow them from seed, let em go for a few years, starting new ones each year too. Gonna have to get a better handle on issue of why they do or don't make seeds and why the do sometimes and sometime not. I haven't had any luck cloning them from cuttings, they are very different from batatas in that respect.

(add) O'yea the inside of the inside of the roots is snowy white and 24 hours after eating one, no ill effects.
 




 

« Last Edit: 2019-09-30, 11:48:00 AM by reed »

ImGrimmer

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I noticed that wild Calystegia (a european native Ipomoea relative) is a very bad seed producer too. I visited a patch with wild Calystegia pulchra for several years in search for seeds. There were barely any to find and these have a bad germination.
When I check seed capsules of the more common white Calystegia there are often none to find.
I always wondered what that means. Interesting that pandurata has a similar behaviour.

reed

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In my research on sweet potatoes I'v come across mention of this several times in relation to other Ipomoea species. Most talks like they are just not self compatible but based on my observations at least with pandurata that just isn't true. They make seeds sometimes and sometimes not, some environmental variable must also be involved, it seems to me.   

Chance

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Reed,

You got seed from batatas x pandurata?  I’m getting a pandurata population ready here, in their 2nd year all 3 of mine flowered and I’m harvesting seed.  I’m going to try the roots soon.  A batatas x pandurata would be really interesting and is high on my list of wide cross attempts.  Are you gong to use batatas true seedlings to pair in the cross? You might want to cut some of the styles of the batatas once you set it up because it’s tricky for the pollen to get all the way to the ovary. 

Wishing you success

reed

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I pollinated several batatas flowers with panurata pollen but only got those two seed which did not sprout. Not 100% sure they  were crossed cause my technique is a little sloppy and a bee might have sneaked in there too.

That's great your pandurata are flowering in their second year. If mine do that so I don't have to drive somewhere to collect pollen I'll be able to make lots more attempts and also the other way, with pandurata as mother.

I have a pretty good assortment of my own seed grown batatas that easily flower, I'll use them in my attempts. What do you mean  by cutting the style?

Chance

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About the strange (in-)compatibility of pandurata, this what genus expert Ron Kushner had to say in a recent FB post: “Cross fertilization tends to work if the plants are from significantly different populations, although plants within the same general vicinity tend to be incompatible also for most of the time , although the cross incompatibility may change over a period of time that only the plants seem to know , hence the mysterious part of the story.”  Nevertheless, more genetically diverse pandurata more frequently produce more seed. For the amount of flowers my 3 plants produced, the seed harvest had been a fraction of that. 

Reed did you come across the Russian (of course they did it first) research on batatas x pandurata?  https://www.docdroid.net/AKiHsfR/101093-at-oxfordjournalsjhereda103982.pdf?fbclid=IwAR1NIfdIlxt-7hdwVFWXm6RUVys2fOqcglFqSzVb56mgZ5c4K4TOZgbT5D0

It looks like pandurata as a mother fails, and batatas x pandurata is successful at around 2%.  Not really much information about the hybrids themselves.

Cut style pollination, also called stump pollination is where you chop of the stigma and a part of the style somewhere above the ovary.  It’s just a hypothesis that it could help in Ipomoea, based on observations of pollen tube pathway irregularities and growth tube restriction of batatas. 

Also promising is the application of growth hormones to the flower stalk after pollination.  https://rd.springer.com/article/10.1007/s10681-009-9967-7?fbclid=IwAR3OK-YlV0zqPYc8VdsWhjYKFnjOSRlZjOV3ZNvk4JR7AeUgNjje403Gn7k

“To overcome interspecific cross-incompatible barrier, we applied 100 mg/l GA3 + 50 mg/l 6-BA to the stalk of the pollinated flowers. The treatment was conducted for seven consecutively days for good fruits and seed sets.”  These crosses are more genetically distant than pandurata, and despite that pollen fertility of the F1 approached 80%.

I won’t be gardening next year, but hope to set up an experiment after that.  This fall I’m going to divide one of the pandurata roots in sections and see if that works for propagation. 

Edit: I see you tried vegetative propagation already, too bad it didn’t work.
« Last Edit: 2019-10-05, 10:00:44 AM by Chance »

reed

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I had not seen that paper before, interesting reading. The 2% success is in line with other papers I'v seen. Have to wonder about lack of follow up on what happened after that.

I din't try root divisions of the pandurata, just cuttings. They failed to sprout roots in water, in soil, in sun, in shade. I don't know of anything easier to propagate that way than batatas.

Chance

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Which other papers talk about this cross?  I only know of one which references this one. 

Have you seen this report on the edibility of leptophylla?  Makes me want to try this one as well.

https://www.pullupyourplants.com/unusual-garden-plants/2018/2/12/bush-morning-glory

Descriptions like “crisp and sweet” are said to apply to macrorhiza which is supposed to be comparable to jicama, and can be eaten raw.  The three are closely related — leptophylla, macrorhiza, and pandurata.
« Last Edit: 2019-10-06, 11:59:18 AM by Chance »

reed

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O'goodness I have lots of papers saved but there is one of my favorites cause it talks a lot about inheritance of various traits in batatas, most of my work has been with batatas.
https://digitalcommons.lsu.edu/cgi/viewcontent.cgi?referer=https://scholar.google.com/&httpsredir=1&article=1843&context=gradschool_disstheses
It's rather lengthy and only mentions inter-species crosses kind of in passing. 
Quote
Almost complete failure has resulted from m o d e m attempts to hybridize Ipomoea species. Toutine (104) reported capsules formed from crosses of batatas X JL. fastiglata. _I. batatas X _I. macrohyma. and batatas X I. pandurata. No further report as to whether these capsules contained viable seed was found
I know I've seen it other places too, will do a little more digging.

I'm not at all familiar with leptophylla but after reading that paper I tracked down some seed on Etsy. May have to add it to my collection.

« Last Edit: 2019-10-06, 03:24:33 PM by reed »

reed

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I don't know much about such things, never tried it before but I think I might try grafting next year. Assuming my pandurata vines take off good which I expect they will I can easily try grafts in both directions and see what happens. Supposedly there is possibility of gene transfer that way so maybe if that happened it would make cross-pollination more likely. Wish I had thought of trying it this year. Actually might not be too late, I can stop and grab some pondurata stems and see if they will take on a batatas trunk. Maybe I could keep it as a house plant, not likely I suspect but could be fun to give it a try. 

Richard Watson

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Just looking up Ipomoea pandurata out of interest, says here it could be poisonous https://pfaf.org/user/Plant.aspx?LatinName=Ipomoea+pandurata
Changeable year round climate with warming winters - just under 500mm average yearly rainfall. 20 years of soil improvements plus sub soil top soil reversal means my garden beds are about half metre deep. Below that is 100's of metres of alluvial out wash from the Southern
alps.

reed

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Richard, seems like I have seen that somewhere before. I only ate a small piece, maybe an inch and a half long by by 3/4 inch thick. There was no bitterness or other bad taste at all, just very mildly sweet.  Still something to look into further.

That other ipomea that Chance mentioned is described in the link he posted as also being referred to as manroot and I've always heard that in reference to pandurata. Something else to research more this winter.

In the mean time mostly just for giggles, I dug up one of the smaller  pandurata roots I'd buried and split it down the middle and inserted a shaved down stem of one of my best plants. Doubt much comes from but if the batatas stays alive for any time at all and without sprouting it's own new roots then I might be on to something.   

Introducing I frankenbatatarata.
« Last Edit: 2019-10-07, 04:52:02 PM by reed »

Chance

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Richard, as I understand it the poisonous idea came because livestock don’t browse the foliage.  The mature foliage has a milky sap that is very astringent.  The tuber isn’t dangerous but I think if it was too mature the bitter components would cause digestive upset, but it wouldn’t be palatable anyway.

Reed — fun!  I would like to hone herbaceous grafting skills at some point.  If one of them takes, there are a couple things to keep in mind depending on your goals.  If you want to maximize the chance of sexual crossing, the idea is to graft the mother to be on the rootstock of the species that will be the pollen donor.  If you want to maximize the potential for genetic transfer from a rootstock in the seed of the scion, that’s where you use the mentor graft technique.  You basically keep a lot of foliage on the rootstock and prune all but a couple leaves at the growing tip of the scion, eventually collecting its seeds.  Ideally you want to use a scion in a state of plasticity.

reed

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Reed — fun!  I would like to hone herbaceous grafting skills at some point.  If one of them takes, there are a couple things to keep in mind depending on your goals.  If you want to maximize the chance of sexual crossing, the idea is to graft the mother to be on the rootstock of the species that will be the pollen donor.  If you want to maximize the potential for genetic transfer from a rootstock in the seed of the scion, that’s where you use the mentor graft technique.  You basically keep a lot of foliage on the rootstock and prune all but a couple leaves at the growing tip of the scion, eventually collecting its seeds.  Ideally you want to use a scion in a state of plasticity.
Thanks for the input, couple questions;
What is mentor graft technique?
What does state of plasticity mean?

Much to my surprise the batatas stem I used has not croaked. The large leaves look pretty bad, I probably should have removed them, but the small top leaves look perfectly fine. I'v been careful not to get any water on the graft so if they are getting any water or nourishment at all it is coming from the pandurata root. I'm scared to remove those larger leaves now for fear of disturbing the graft. something other than gorilla tape might have been better to secure the connection but that is what I had on hand.

I think I'm gonna try another one only use a different technique. I got piles of discarded batatas vines with lots of little roots that have buds or growth on top. I think I'll use a drill bit or something to excavate a little hole in the top of a pandurata root. Then shave down the tip of the batatas root to fit it. I figure it will give a better connection with less exposed injury as in the split part of the one I have now. If it works I may be able to keep it alive till next spring and if it blooms pollinate with pandurata. 

« Last Edit: 2019-10-09, 06:58:49 AM by reed »

Chance

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Here are a couple mentor graft illustrations:

https://www.google.com/amp/s/www.researchgate.net/figure/Mentor-grafting-A-Non-graft-normal-plant-as-control-B-Mentor-graft-scion-leaves_fig2_270661829/amp

https://www.semanticscholar.org/paper/Historical-and-modern-genetics-of-plant-graft-Liu/1039b16b62b0ca3eb3fb83fcd6bc12b2b5ba28fa/figure/1

Mentor grafting is basically about creating a developmental asymmetry to maximize flow into the scion.  Plasticity is most expressed in young hybrid plants—they might be throwing out different fruit sizes, flower colors, leaf shapes, etc.  They are most susceptible to graft induced variation.  It can also happen, to a lesser degree, when moving a plant to a different climate where it starts to have epigenetic changes and change phenotype.  Or in a genetically diverse modern landrace.

You can use super glue to secure the graft as well.  This guy does it with tomato: https://www.youtube.com/watch?v=5Fd6tBQTTAg

The hole method is called the hole insertion graft, commonly used in Curcurbita for disease resistant rootstock. There are videos of it on YouTube also.  https://www.researchgate.net/figure/hole-insertion-grafting_fig1_316511579

Approach grafting is also good for herbaceous plants since they dry out so easily.  Either way a humidity dome is pretty crucial for the healing stage of herbaceous grafts.  As well as shade for a period and then gradually increasing light. 

Look into vegetable graft healing chambers. http://edis.ifas.ufl.edu/hs1232


« Last Edit: 2019-10-09, 11:29:21 AM by Chance »