Breeding with wild tomato species

[Garrett Schantz]

Considering a good portion of my peppers still haven't germinated due to cold temperatures, I have decided to put the no-germ plants off to the side and use the lighting space for more tomatoes. I can just buy some generic pepper plants from a nursery if I really want to. A lot of my tomatoes that I started early actually ended up with red leaves. Suppose this might influence epigenetics of all of my tomatoes...

Ordered Matt's Wild Cherry - not really a "wild tomato species" - appears to have been collected from feral plants in Mexico.

Also ordered Alberto Shatters, images provided on Restorationseeds show all exerted flowers. Leaves seem to look like a another unique pimpinellifolium. Being exerted means it probably has a higher chance of cross pollinating / mutating. Could have some fun resistant traits due to that.

Adding a bunch of currant tomatoes into an exerted group would be interesting. With how diverse pimpinellifolium is, I wouldn't be surprised if there are types that could act as a pollen donor to wild species. Of course I would need to request germplasm for the more diverse types, they just aren't really sold / used outside of breeding. Some of these diverse types actually aren't used in breeding all too often either because they lack research or they have other alternatives.

Alberto Shatters is already pretty exerted, so it might be a good parent to begin the population with. My pimpinellifolium x habrochaites F2 should have some exerted offspring as well. They will probably intermix with themselves and each other. Alberto Shatters will hopefully cause the exerted gene to dominate when they cross.

Might be able to just stick some saladette promiscuous tomatoes around them to introduce a larger fruit size.

Cheesmaniae and Galapagense could get tossed in as well. Salt / maritime tolerances could be helpful for some people.

Also adding in Muchacha!, Weight in Gold, Copper Currant, Wild Gem - these have wild ancestors, mostly habrochaites.

Orange Currant and Blue Cream Berries tomato are notable due to small, pointed black-brown seeds. Possibly descended from habrochaites or another wild species.

It does seem that some people don't want smaller flowered tomatoes(I don't like them either - will select against them using habrochaites), or things that can set the projects progress back. So these will be grown in a separate spot, somewhat isolated enough that they won't intercross frequently with the main group. Would probably plant habrochaites, peruvianum accessions around them just to see what happens. Also some saladette promiscuous tomatoes. Ideally I end up with fruity orange-purple currant / cherry tomatoes with high disease / stress resistances.

If I get anything notable out of the group, immunity to certain diseases / pests, high spring or fall frost tolerances - I will move those into a separate group to allow try and stabilize the traits. Culling the whole group might result in lost traits. I could also just wait enough generations that everything gets mixed together well enough that I can cull plants without having to wonder if I am killing plants with important genes.

This also gives me an opportunity to select out different habrochaites flowers than what we already have in the group, possibly some ornamental fruits as well. If I had S.sitiens or a scented flower type of tomato, they would be tossed in as well. Any other wilds that don't normally seem to have any importance could be added in.

I can't test resistances for everything, so I will probably end sending seed out if anyone wants any - the population would end up with more diversity as well. Unsure if anyone wants to possibly pollute their populations. Seed sharing would be towards the end of the season. The population would take a few years to really develop into something nice, unless I manage to grow some inside - start a second crop later in the season.

[William Schlegel]

Alberto Shatters sounds like a good pimpinillifolium, nice find. I was very happy in 2019 when I realized the pimpinillifolium Andrew sent me had good exsertion. I have some probable hybrids with Alan Kapuler's Golden Tressette already planted. I think that just growing and seed saving multiple exserted varieties in close proximity should result in lots of hybrids.

[William Schlegel]

The bleaching process was successful. The LA2329 is the first tomato to germinate. Also the 2020 grown LA2329 is germinating much faster than the original packet.

[Garrett Schantz]

The bleaching process was successful. The LA2329 is the first tomato to germinate. Also the 2020 grown LA2329 is germinating much faster than the original packet.

Looks pretty nice.

There is a LA2329 PDF that I found online: https://tgc.ifas.ufl.edu/TBRT%202018/PestR/Introgression%20of%20type%20IV%20trichomesand%20zingibereneinto%20tomato%20from%20S.%20habrochaites,%20LA2329%20Current%20status%20Synder.pdf

Mentions all sorts of nice things. Suppose you might need to capture some spider mites and have them make a home on bean plants like in the study. Apparently the insect resistance which seems to be IV trichomes and zingiberene(ZGB) is pretty dominant, being found in early generations of hybrids. But higher concentrations of zingiberene seem to be recessive.

If zingiberene sounds familiar, its because it is also found in Ginger(Zingiber officinale). Unsure if any flavors are imparted into the fruits from these chemicals though. Would be a good bonus. Suppose you could search for a pungent tasting fruit.

High brix, small statures, high flavor and concentrated fruit set are also mentioned. Seed fertility issues are mentioned, but that seems to be the norm with wild tomato breeding anyway.

Testing zingiberene levels could be done, but it seems like it will require a bit of a setup.

[William Schlegel]

Yes esentially the goal of my acquisition of this accession LA2329 is the replication of these works with arthropod resistance. The initial reasoning is that for my direct seeding project direct seeding works great for me usually. However Joseph and Andrew have had failures. Joseph implicated mites as a possible culprit. So possibly if Arthropod resistance is an answer to that then this accession might have answers. If we can replicate the work which isn't certain especially not without a way to identify the best resistant seedlings. Also did you notice in the pdf that the researchers ended up subdividing LA2329 into different sub populations and some of them were much more effective? Garret you are in the same USDA zone as me and Andrew and Joseph are Rocky Mountain gardeners like me. Definitely hard for any of us to replicate the growing conditions at the TGRC. That tends to lead to rapid genetic shifts. Also strong selective forces can lead to just some random genetic loss. Which is why I went ahead and planted the whole rest of the packet this year. To try to grow the best growout I can of the material. However, no guarantee that even with a hopefully large as possible population that there won't still be genetic shifts. Also I've locked in some genetic shift with last year's two reproducing plants out of ten or twelve. That's probably 100 seeds to around 35 left in the original packet. So it is possible just from random change that we could loose the best genetics for arthropod resistance. Still I think it is well worth a shot. Also I don't trust universities not to keep the material from the university studies proprietary. My work will get OSSI pledged probably sooner than later. Actually it is possible that via Big Hill the whole promiscuous project may already be OSSI descended. It is also quite possible even probable that the existing promiscuous populations might have crossed with the LA2329 I grew out last year. Actually if we can use the existing promiscuous project we might be able to avoid some of the typical infertility problems with wild crosses. Might not but the promiscuous plants are already using habrochaites S allele self incompatibility. So the idea is to use these LA2329 as another habrochaites cytoplasm population within the larger project. Last year I grew 25% habrochaites 50% Big Hill all around the LA2329 row and the existing habrochaites cytoplasm population just in one row to the east. This year I plan to grow one R18 plant and a small pot of the existing habrochaites cytoplasm population with the LA2329 population. I would also really like to get some LA2329 pollen parent crosses made with something like Mission Mountain Sunrise my short season blue bicolor. Precisely because F1's should contribute pollen back to the habrochaites cytoplasm population next year.

[Garrett Schantz]

More notable Peruvianum seedling images from Joseph / Experimental Farm Network.

First image isn't so good, my phone wants to take very detailed photos, having problems focusing on leaves. Doesn't help with the seedling being very small. Anyway this one has leaves that cup slightly inwards. Its quite fragile, slow growing. Looked interesting enough to keep though.

Second image had a much larger cotyledon than the other peruvianum seedlings, so I saved it. First set of true leaves different enough from the more common leaves that I have been seeing - so I singled this out from the rest. Seems to be growing more quickly than the other seedlings as well. Elongated, wider leaves than the others.

My habrochaites x pimpinillifolium are starting to get their first set of leaves as well. Too small right now to really look for any fun leaf types, pretty low germination as well.

[Garrett Schantz]

Found this PDF while looking for information about an insect resistant habrochaites accession. https://nph.onlinelibrary.wiley.com/doi/pdf/10.1111/nph.14130

Talks a good bit about intraspecific crosses being linked to SI / SC.

Pollen-pistil interspecific reproductive barriers (IRBs) are
mechanistically linked to SI. Unilateral incompatibility (UI), in
which fertilization occurs in only one direction, is a type of IRB
that is common between SI species and related SC species (Lewis
& Crowe, 1958; Pandey, 1962, 1981; Levin, 1971; Bedinger
et al., 2011; Baek et al., 2015). In a number of plant families, UI
follows the SI x SC rule: interspecies crosses fail when an SI
species is used as female and an SC species is used as male, but
the reciprocal cross is compatible (Lewis & Crowe, 1958; Hogen-
boom, 1973; Murfett et al., 1996; Baek et al., 2015). SI factors
including S-RNase, HT protein, Cullinl and SLF proteins have
been shown to participate in this type of IRB (Covey et al., 2010;
Li & Chetelat, 2010, 2015; Tovar-Méndez et al., 2014). How-
ever, while it is clear that UI and I mechanisms share significant
overlap, it should be noted that additional UI mechanisms exist
that are not dependent on S-RNases (Murfett et al., 1996; Kondo
et al., 2002; Covey et al., 2010; Eberle et al., 2013; Baek et al.,
2015).


Solanum habrochaites has undergone at least two independent
transitions from the ancestral Si mating system to an SC mat-
ing system at both its northern and its southern species range
margins (Martin, 1963; Rick et al., 1979; Rick & Chetelat,
1991). Previous studies identified one northern SC population
that lacks expression of S-RNase (Covey et al., 2010), presum-
ably as a result of the insertion of a transposable element (TE)
in the promoter region (Kondo et al., 2002). UI has been
demonstrated between S. habrochaites and SC species in the
tomato clade, wherein fruit is only formed when the SC species
is used as female in reciprocal crosses (Mutschler & Liedl,
1994; Sacks & St Clair, 1998). Solanum habrochaites pistils
reject pollen tubes of Solanum lycopersicum, although, interest-
ingly, SC population LA0407 displayed weakened IRBs com-
pared with Si population LA1777 (Covey et al., 2010; Baek
et al., 2015). UI has also been observed between marginal SC
populations and central si populations of S. habrochaites
(Martin, 1961, 1963, 1964).
We hypothesized that the transition from SI to SC would be
associated with specific mutations in SI factors and changes in
floral morphology, and that the transition would influence both
interspecific and interpopulation pollen-pistil compatibilities.
To address these hypotheses, we utilized morphological, func-
tional and molecular techniques within a biogeographic context.
We focused on S. habrochaites populations at the northern range
margin that vary in mating system (SI, SC or mixed SI/SC popu-
lation) and identified differences in floral characters. We assessed
pollen-pistil interactions of these populations with other species
in the tomato clade and with each other. Further, we ascertained
whether known pistil SI factors (S-RNase and HT proteins) are
present, and identified a loss-of-function S-RNase allele in a
subset of populations.


This has made me wonder about a few things. SI LA1777 can hybridize with SC Lycopersicum / Pimpinellifolium. SI Chilense and SI Arcanum seem to behave the same way (being the fathers) for the most part.

Everyone has been searching for Wild x Domestic backcrosses to the wild parents using S alleles/ SI. But I have only seen SI LA1777 being used on the habrochaites side of things.

If we manage to get a population of SI Wild x Domestics, and then cross them with SC Habrochaites accessions - would this result in a hybrid with habrochaites as the mother?

Could be worth a try - I don't have any SC habrochaites though.

Tossing in a SC Habrochaites that can pollinate LA1777 could introduce SC into the group. I would only do this because most of the SC Wild accessions have very small flowers, difficult to emasculate without damaging everything inside. Exerted SC Habrochaites might be ideal for this experiment.

Assuming the flowers are smaller because they don't need to attract as many pollinators to deal with SI...

The Promiscuous population probably already has a mix of SI / SC, so there isn't much to worry about on that end of things. Different mixtures of S alleles are probably present which also helps.

I haven't seen any research about SI Domestics x SC Wilds. Worth a try I suppose.

Joseph's high-habrochaites percentage crosses might work well as a SI parentage for SC Habrochaites.

Of course this is just an idea. Introducing SC habrochaites lines could mess up someone's germplasm. Unsure if it would work either.

The PDF might help understand why LA2329 wasn't setting fruit with LA1777, or with itself very well. Could be a mixture of different S alleles found within the population. Could be that the original seed was bottlenecked. Worth seeing if it managed to donate some pollen to LA1777.

https://www.youtube.com/watch?v=xlj7BE0tVC0 - https://davesgarden.com/guides/pf/showimage/318318/
This YouTube video / Davesgarden gallery shows a pretty similar habrochaites to what I grew last year. I didn't buy the seed from scirpidiella / lupineaster though. Glossy / huge leaves, purple stems, shrub-like. Unsure if mine was self compatible like his though. I had flowers aborting when there was only one plant, so I am assuming SI. Rare to find video / images on these plants.

Unsure if the one I grew is already included in the Neandermato. Either way, I have a large glossy leaved habrochaites x small leaved pimpinellifolium. Bunch of F2 seeds are growing in a pot right now. Both parents were low growing, not a favorable trait as leaves touching the ground usually creates blight problems here. I usually just cut off the lowest growing parts - solves the issue. Believe Andrew said he liked this trait though.

[William Schlegel]

I plan to keep it simple and mainly focus on one wild accession at a time.

[Garrett Schantz]

I plan to keep it simple and mainly focus on one wild accession at a time.

Sounds good. Should be able to stabilize traits better this way. I might mix mine a bit, I can backcross if I need to.

[Garrett Schantz]

Fun looking habrochaites image I found on Twitter. https://twitter.com/orchidhunter/status/1195481620419088384?s=20

Fruit has an interesting marking towards the bottom. Appears to be black - usually white on habrochaites.

[Jeremy Weiss]

Looks more like dark green to me. Sort of like a Green Zebra habrochates

[Joseph Lofthouse]

I used LA1777 only for the initial pollen donation to domestic tomatoes.

The rest of the S habrochaites, that I work with, is a mixed population that includes, but is not limited to: LYC2568, LYC2885, LYC2961, LA1777, and a  no ID that I bought from a seed company. I call this mixed population Neandermato. 

Neandermato swapped pollen with the [domestic X LA1777/pennellii] population. The mixed interspecies population is very capable of pollinating pure habrochaites. Four of the five back-crosses that I made are to Neandermato. One is to LA1777.

The most important trait to me in tomatoes is the self-incompatibility trait. Therefore, I won't knowingly use any of the SC habrochaites lines.

I have not done the work to rigorously isolate and identify the SI varieties. Therefore, I select for huge, promiscuous, open, bright flowers, figuring that even if what I'm working with is SC, at least it will be highly attractive to pollinators, and very capable of crossing facultatively.

[William Schlegel]

http://jandlgardens.com/xencart/index.php?main_page=product_info&cPath=78&products_id=701

Lee made another fun sounding wild genetics tomato- Wild Gem see link. Too bad it is sold out.

Ooh Lee is cryptic in his descriptions sometimes.

Which species of tomato from Ecuador?


I think I for one had forgotten all those other habrochaites accessions Joseph incorporated at least in part. Its easy to remember those early photos of LA1777 alive after all the other tomatoes had frozen.

[Joseph Lofthouse]

Hmmm. I was still keeping records in 2016.

I think that the plant with the huge flowers, that survived for 2 months after the other tomatoes had died was LYC2568. It also sailed through the spring frost tolerance trials. Definitely not LA1777, which is a delicate plant. If I were to restart this project, I wouldn't use LA1777. I would choose one of the accessions with huge showy flower clusters.

Little did I know what a garden journal entry from February 2016 would turn into.....

[Kevin Collignon]

I am planning on growing out wild tomatoes this year for the first time and I am hoping to create a mix of a bunch of all the wild tomatoes I can get and trying for a hybrid swarm and then begin selecting from that in later generations. If there a specific number of plants that should be grown together for the most genetic diversity? Also I have a few heirloom variates such as black beauty, and brads atomic grape tomatoes that I would like to contribute the color of to the gene pool. Would you suggest just placing these variaties in with the wild mixes so they have a small chance to cross with something else or would their be another method to introduce those types of colors?