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Post by Joseph Lofthouse on Feb 8, 2011 22:22:47 GMT -5
This winter I am growing true potato seeds that I got from GRINS with the hope that by spring I will have tiny tubers to plant. They were collected in South America. I am also growing Hanna's potato and Ella's potato as controls. Hanna's and Ella's are from plants that produced lots of seeds last summer.
One of the potatoes is named PI 558369. It germinated in 4 days (twice as fast as the others), and has made 10 times the growth of any of the other potato varieties. I'm thinking it may have great potential as a direct seeded potato. And in any case, with the vigorous growth it's much easier to work with than the typical slow growing potato seedling.
It is described as: Solanum tuberosum subsp tuberosum. Isla Gran Guaitecas, Aisen, Chile. Tubers with purple skin. Fruits present. 3 feet elevation. 44 degrees south.
As far south as it was growing it may be a diploid rather than the more typical tetraploid.
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Post by garnetmoth on Feb 8, 2011 22:45:38 GMT -5
sounds fascinating! Keep up the good work and let us know how it goes!
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Post by DarJones on Feb 9, 2011 1:43:20 GMT -5
Joseph,
It is id'd as tuberosum and has rapid growth. You don't usually get that except in a tetraploid. You can tell when the plants get about a foot tall by the leaf shape.
DarJon
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Post by Joseph Lofthouse on Feb 9, 2011 3:09:29 GMT -5
I'll be able to tell if it's diploid/tetraploid? Or if it's really S. Tuberosum? What's the difference in leaf shape? I'm growing: diploid S. stenotomum from 13,000 feet in Bolivia, diploid S. vernei X2 from ~10,000 feet in Argentina, S. tuberosum X3 from ~44 degrees south in Chile S. tuberosum X2 from the usa garden.lofthouse.com/botanical-potato-south-america.phtmlExcept for the one accession they are growing slow-----------ly. It was collected in the wild at the southern most edge of the wild potato range, an area in which diploid S. tuberosum are known to grow. I thought that in general tetrapoid tissue grows more slowly than diploid tissue? Here's a photo:  And yes, there really are things growing in the right-side pot if you get out a magnifying glass. |
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Post by tatermater on Feb 9, 2011 5:27:22 GMT -5
Joseph,
First of all, thank you for mentioning me on your blog as a source of TPS.
I have alerts on my emails about anything TPS, therefore I read your topic post about the PI number that germinated in four days.
TPS has a germination inhibitor that retards the germination rate on new TPS...so much so that older seed within the GRIN collections of twenty years may germinate faster and stronger than new seed. I wouldn't put too much weight into thinking that the seed you have can be duplicated for direct seeding ease with your own seed of the same accession.
The collection data of 1990 shows several potato collections on those islands south of Chiloe. The climate where your PI accession was collected is an area that has temps from 62 to a low of 43, definitely a cool mild wet climate. It would have more relevance to me here in the Pugot Sound area than in Utah.
I notice that many of the sister collections had a variety of skin colors but almost always white flesh. The potatoes are growing seemingly wild but most often in old abandoned fishing camps. The population is sparse but has been around for many thousands of years. Most of the collections had no berries, but it is good to have one that sets berries in the wild. How it does in the heat of Utah is another thing.
All of the collections like your PI 558369 are tetraploids according to the collections made by the three gentlemen listed as sources. You can usually tell the diploids apart from tetraploids by the leaves....slightly larger and fewer leaflets than diploids. I don't see any reference to triploids and not sure where you got the 3X from.
The first Chilean potatoes I have grown were collected by D.S. Correll in 1952, and I got those about ten years later. For the last 50 years, most of the Chilean potatoes have been near worthless to me. Hope you have better luck that I had. It is really important to breed them with other material; their cool wet maritime climate needs will do all kinds of things in hot climates....long stolons, poor yields, etc. My guess is too, that the berries will not form well in hot weather from your seedlings.
I wonder what the relationships would be between the Ozette potato from the Makah tribe here in Washington and the Chilean Islands potatoes. I bet quite a bit. I love the fact that both areas have had histories of shell dumps on the sandy shores and near feral potatoes surviving in populations of twenty to 100 plants.
On my website newworldcrops.com where I list many potato TPS lines, I should make some story lines connecting varieties like Huagalina that has flavor and the grand-daughter Yungay having a similar flavor. Yungay will be part of many high flavored potato pedigrees in the future.
Tom Wagner
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Post by Joseph Lofthouse on Feb 9, 2011 13:05:00 GMT -5
Tom: Thanks for your years of research and for knowing how to use GRINS to tell a better story about my potatoes.
This week when I was researching wild potato species, I found mention of one that grows wild in Hopiland. Now that could be interesting for my climate....
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Post by tatermater on Feb 11, 2011 22:07:30 GMT -5
Thanks, Joseph I could be a better story teller of the GRIN seed inventory if I just concentrated on different subjects and talked with more of the officials who collect, maintain, or otherwise study the accessions on site. But as you mentioned Hopi and potato and wild species....Hmmm...interesting key words! Oh, yes...I remember the two species that I know of.....here are a few quotes from the internet.... www.springerlink.com/content/6n27575uq8112145/I probably should start working again with jamesii...I have in the past but concentrated on good eating potatoes a bit more than jamesii. I remember either growing out seedlings or tuber families and it does seem like one has to wait up to two years to grow some of these materials. You can wait forever for them to sprout....and the small size tubers usually dry out first. www.fireflyforest.com/flowers/2724/solanum-fendleri-fendlers-horsenettle/I have done some crossing with the former name fendleri now known as Solanum stoloniferum. Wow! Some really wild stuff! It is going to take be a while to get rid of the wild and tame it down a bit. Naw...I am not going to go into a lot of detail on these wild species now. I am tired from mailing out 15 orders of mostly TPS...True Potato Seed. Tom |
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Post by mnjrutherford on Feb 12, 2011 7:41:30 GMT -5
Horse nettle? There's something edible on horse nettle? Come on. You're kidding right? Those things are like ... like... what would happen if wall street bankers suddenly developed thorns! If they truly produce tubers, they are at the end of more than 10 feet of root systems! With all the nasty thorns, I can't really see why anyone would WANT to use them in a breeding project. If you want seed though, I can send you some.
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Post by blueadzuki on Feb 12, 2011 11:11:13 GMT -5
Horse nettle? There's something edible on horse nettle? Come on. You're kidding right? Those things are like ... like... what would happen if wall street bankers suddenly developed thorns! If they truly produce tubers, they are at the end of more than 10 feet of root systems! With all the nasty thorns, I can't really see why anyone would WANT to use them in a breeding project. If you want seed though, I can send you some. You are thinking of regular horsenettle, Solanum carolinense. Different species. Common names are often really non-specific. |
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Post by mnjrutherford on Feb 12, 2011 13:09:16 GMT -5
ahHA! Thank goodness you said that Blue! I had no idea and the thought of someone purposely cultivating the damn things was making me crazy! Unfortunately for you, I now need to know something else.... How closely related are they?
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Post by blueadzuki on Feb 12, 2011 14:37:08 GMT -5
ahHA! Thank goodness you said that Blue! I had no idea and the thought of someone purposely cultivating the damn things was making me crazy! Unfortunately for you, I now need to know something else.... How closely related are they? Not very close at all. Solanum is a very big genus. According to a site I found the two are in different subgenera (i.e. one step below genus. S. carolinense is in the Melongea subgenus (the same one as eggplant) while S. stoloniferum is in Petota (the same one as potatoes) |
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Post by spacecase0 on Feb 12, 2011 21:50:14 GMT -5
I am confused as to how the diploid/and tetraploid potatoes differ,
I know they have a different number of chromosomes, but does it matter much ?
I have looked on the net and they say that some are converted to diploid for breeding and then back to tetraploid to get larger harvests,
but I can't figure out how you would do that, or if it is worth bothering with.
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Post by Joseph Lofthouse on Feb 12, 2011 23:50:02 GMT -5
Doubling the chromosome number is fairly straightforward: Apply a spindle poison to actively growing tissue. That stops the chromosomes from separating and creates tetraploid tissue from diploid tissue. A commonly available spindle poison is the herbicide oryzalin: Applied in normal dose it kills the plant. Applied in very low dose (0.002%) on the actively growing point it just messes with the chromosomes without outright killing the plant. Sometimes the new growth can be chimeric with both tetraploid and diploid tissue or even higher ploidies. The diploid tends to grow faster so the stem might curl or things like that.
Doubling the chromosome number is commonly applied to the seedlings after inter-species hybridization: To get offspring that are fertile especially if the two parents have a different number of Chromosomes.
(I'm expecting that it will be necessary in my attempt to breed a perennial watermelon to use oryzalin to create a tetraploid, because one of the parents has 10 sets of chromosomes and the other has 11 sets. I wonder if it would be advantageous to create the tetraploids first and then hybridize the tetraploids?)
Breeding with diploid tissue is rumored to be simpler because there are only 2 possibilities for each chromosome instead of 4.
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Post by mnjrutherford on Feb 13, 2011 12:00:14 GMT -5
LOL Blue, you are wonderful. Thank you for the explanation. Sadly, I feel as though the doors of the elevator I was waiting for just opened and there is a naked man standing inside. I stand there gaping in shock, no thoughts at all running along the nervous system, the doors close, and I'm still waiting.
Nevertheless, I am appreciative and grateful! =o)
Joseph, I can't even read your reply to Space without shielding my eyes from the light!
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Post by atash on Feb 14, 2011 0:59:14 GMT -5
There are differences between different ploidy levels. Diploids evolve much faster. I think that is what Joseph is alluding to as regards the rumor regarding diploids being easier to breed. Higher levels of ploidy result in redundancy which is a mixed blessing. One interesting benefit is that you can have multiple alleles on the redundant chromosomes to produce something with an effect similar to "hybrid vigor" that breeds true. On the other hand, if you had a new or rare allele for a given gene that wasn't already on one of the redundant pairs of chromosomes, it would be hard to get it there without moving back down to diploidy and then back up to tetraploidy. This is why polyploid plants evolve slowly: a new favorable mutation is hard to duplicate on the redundant chromosomes, and therefor its effect gets watered down. I would guess that there is some "overhead" for total amount of genome. I recall reading that someone decided that octaploid was as high as practical for wheat and its amphiploid relations. Wheat already has a gigantic genome--longer than a human's. But the record so far that I am aware of is that of Paris japonica. Generally speaking, tetraploids are often physically bigger and more vigorous than their diploid counterparts. The effect seems to diminish at higher ploidy levels. Spacecase, not surprisingly, Tom Wagner's diploid potatoes tend to be small--roughly golf-ball sized. That is almost certainly due to being diploid. OTOH they are quite vigorous. Usually more so than the tetraploids. Probably because they consistently outcross, and therefor often show some hybrid vigor, and also because they are faster to breed. The plants themselves are typically finer-leaved, but not particularly small in total size of the plant. You get more but smaller shoots, leaves, and potatoes. One problem with polyploids is that if they interbreed you often get plants with odd-numbered levels of ploidy, for example diploid x tetraploid results in triploids. Commercial breeders often do that on purpose to intentionally create sterile crops. I have had some unpleasant experiences with that in some commercial crops that were not advertised as being triploid or sterile. Could not save the seeds, as none were produced.  Plants with odd numbers of ploidy levels are not always sterile. On rare occasions something will happen during chromosome splitting that resolves the unmatched chromosome. Someone I know waits patiently for the occasional seed on Knifophia thompsonii var snowdenii, which is triploid. Some types of plants for some reason often resolve their odd chromosomes; Fuchsias, for example, or wheat. I don't know why; I'm not a biologist. |
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