Open Source Plant Breeding Forum

I don't know that we have a Solanum pimpinellifolium thread like we do with some of the other species tomatoes. So this is my attempt at starting one.

Our closest is the thread Reed started on his enviable natural crosses thereof http://opensourceplantbreeding.org/forum/index.php/topic,229.msg2433.html#msg2433

I have been growing Solanum pimpinellifolium or closely related domestic tomatoes for years.

The first varieties I or my family grew of currant tomatoes included tomatoes with names like "sweet 100" and "sweet millions". I also have a Sweet Pea Currant from Territorial in my personal seed bank. One of those volunteered in 2016 along with another tomato giving me the idea for working more with direct seeded tomatoes and is in my personal seed bank as 2016 volunteer pimpinellifolium.

Then Joseph and Andew sent me their strains of Solanum pimpinellifolium and Andrew's proved to be modestly exserted. The original packet mentioned that it might contain crosses- and it still might I haven't grown it all out. I think I have some probable crosses between Andrew's pimpinellifolium and Golden Tresette an exserted type bred by Alan Kapuler though I haven't grown out enough of them to prove that the expected red/yellow segregation is there.

Coyote and Sweet Cherriette which are favorites and I have grown them every year since 2017 are also likely have a lot of Solanum pimpenillifolium ancestry.

This past winter I have obtained seven new to me types of these currant tomatoes and am growing out a small clump of each as well as clumps of each of the others in my personal seed bank. My intention with these is ultimately to make some crosses with domestic tomatoes and to try to add some of their diversity into the domestic gene pool. In fact this is one of the more popular tomato species for introgression breeding by university and commercial plant breeders. That past work means that almost any modern tomato that you should choose to make a cross with probably contains some currant tomato genes. It and its relatives Solanum galapagense and Solanum cheesemanii are supposed to be easy to work with and have no special barriers to crossing with domestic tomatoes. Though despite years of growing them I have relatively few known crosses with them in my seed collection.

With their very small fruit size currant tomatoes tend to be early and when crossed with other early tomatoes their small fruit size and weedy nature combines nicely into varieties like Sweet Cherriette that push the boundaries of what is possible in terms of earliness in a tomato. In the past I have noticed some currant tomato like leaf types in many of the very early modern tomato varieties I have grown, and I suspect many have currant tomato ancestry.

I am also concerned that open-source plant breeders may have trouble in the future accessing the vast diversity of currant tomato accessions available in gene banks. These accessions contain important resistances to tomato diseases.

There are two available OSSI dwarfs Dwarf Johnson's Cherry which is the result of a cross with the Everglades currant tomato and Dwarf Eagle Smiley which is a result of a cross with the Mexico Midget variety of currant tomato. More OSSI currant tomato breeding would probably increase resilience of the OSSI tomato lineup. Efforts are underway to do more of this type of breeding with the Everglades currant tomato in Florida. This type of breeding strikes me as reasonable for multiple problems and regions including short season tomatoes for the North, late blight, brown rugose fruit virus, tomato diseases in general, and just for breeding for tomato diversity to withstand unknown future threats. Also, some varieties or accessions of currant tomato have notably good flavor and may be useful in flavor breeding efforts like the Dwarf Tomato Project which was flavor driven to a large extent. Very small tomatoes are popular with children especially.

I have been growing a red-fruited Solanum pimpinelliflolium for about a decade. The seed originally came to me from a neighbor, who said that it had been volunteering in her garden for a decade before that. It has not become weedy in my garden, though it did become weedy in the garden of another neighbor who I shared plants with. Natural hybrids with domestic tomatoes showed up in his garden.

At one time, I tried to increase the diversity of my seed lot by introducing a yellow-fruited strain. It self-eliminated from the gene-pool, because seeds took weeks to germinate, and I only transplant seedlings that germinate quickly.

The extra dose of "tomato flavor" that my strain contains does not please me at all. Bleck!

I've only grown one pimpinellifolium, and it was not one of those with "notably good flavor".   In fact it was so repugnant I would call it inedible.  Really disgusting.  Since I have limited tomato space and have to eat what I grow, it wasn't feasible to make crosses and then grow out and select for "edible".  I wouldn't want the job of tasting for that, either.  :P

I am curious about the range of flavors I'll find with more types this year. The ones I've tried in the past were fine but bred for consumption. Mexico Midget makes Craig Lehoullier's top 10 flavor list in his book. So I am growing it as a flavor standard.

I got golden and white colors from HR seeds. I got the variety copper currant from J&L gardens but checking their website it says that was a Solanum hirsutum cross which is an older name for Solanum habrochaites. I also got Wild Gem from J&L but I am not sure what species that one came from they just say that it was a difficult cross with a wild relative from the jungles of Ecuador.

I think Coyote which is more of a small cherry type is quite good but with off notes.

At various times, I have grown a few pimpinellifolium tomatoes. I remember not liking Ramito de Dulce (red) AT all, though it did produce like crazy (I think the year we grew it was the ONLY year I ever had where we got more tomatoes off our few plants than we could eat.).

Ramito Dorado (yellow) was a LITTLE better, though not as good a producer. And I seem to recall that, when I say it was better, I really mean that the fruit of ONE PLANT was better, and that plant could have been a cross or an off-type given its appearance (I got two shapes of Dorado fruit that year, round (which seems to be normal) and egg shaped (which was the one I though tasted okay).

I WAS going to mention liking Coyote Wild, but it appears that, despite the tiny fruit size, that actually is a lycopersicum.

I also seem to recall there being WHITE fruited currant tomatoes. Maybe those are tastier. (There seem to be two, a general one and a selection called Honey Pearl.)

As I mentioned before I know of no green when ripe currant tomato (there were a few references to one online, but one is clearly referring to Solanum hirsutum, and the other was simply a passing reference to Nahuatl having different words for red and green currant tomatoes (without specifying if they meant ripe and unripe ones, or if there actually WAS a green when ripe currant.)     

Seeds of Diversity lists all the currant tomatoes offered for sale in Canada.  Some are offered by only one company, but others by up to ten companies.

                https://seeds.ca/diversity/seed-catalogue-index/?psp=spk389

Candyland
Cerise Orange
Chiapas
Coyote
Cuatomate Ancient
Gold Currant
Gold Rush
Hawaiian
Humboltii
Matt's Wild Cherry
Petit Moineau
Red Currant
Ted's Pink Currant
White Currant
Yellow Currant

This discussion has reminded me that I have a packet of seed somewhere that was supposed to be second generation golden tresette that turned out to be a red currant when I grew the Golden Tresette next to a red currant. I should grow it to find if it segregates.

Edit: I just planted a pinch of it in a little pot. The packet states that it came from the blue off type I found in the original clump I grew which grew next to Pimpinillifolium.

Golden Tressette was described as being of multispecies hybrid origin including Peruvianum and Pimpinillifolium by Alan Kapuler. So this would be a hybrid of that with something blue hybridized back to Pimpinillifolium. Though no sign of blue in the red berried second generation plant.

I haven't grown this species since sending it to William. Partly because I haven't been able to dedicate time to tomatoes like before (this year is looking good!), but also because this species was highly disappointing to me.

I had heard reports that this species was "bursting with extra tomato flavor", but I found the flavor extra mild and very unappealing. Perhaps I'm like Joseph where lycopene tomatoes just don't appeal to my palate, or perhaps my soil produced different flavors, or both.

Considering the extra small fruit size and that trait is heavily dominant in any crosses I wonder if working with this species would be worth it. I'm leaning toward no. But certain introgressions and lines with resistance genes are already being used, so perhaps those are better than using this species in it's wild state. It does have wide geographic variability and as a species is very genetically diverse.

I personally think this species might be a proverbial dead end.

Andrew I've been calling the strain from you Andrew's Exserted Pimpinillifolium. Any notes in its origins?

Quote from: William S. on 2022-05-06, 09:08:42 AM
Andrew I've been calling the strain from you Andrew's Exserted Pimpinillifolium. Any notes in its origins?

Oh gosh, I'd have to scour any old emails or tgrc papers in the basement.  I'll try and figure it out and get back to you if possible. But considering it is exerted stigma it might have been requested from TGRC specifically for that trait.

Still scouring old seed requests. They are only LA numbers at this point and I have to go one by one seeing if they are the correct species. No luck yet.

But I did find this tidbit from an old email from Alan Kapuler:

QuoteMaybe 10 years ago i crossed S. habrochaites v. glabratum to a cherry tomato (S. humboldtii, the Grape Tress tomato) and developed tomatoes with hundreds of flowers on an inflorescence. Then by growing them in a field of other tomatoes, Dylana, Mario and myself noticed that there were many more crosses than we had ever seen during 3 decades of growing tomatoes and harvesting their seeds. Yes, the centiflors have exerted sigmas and bumblebees and other pollinators love to visit them. I have not compared the different centiflors in terms of exerted stigmas.

Probably best to grow the different centiflors. Last year in growing a cross of S. chilense with likely S. pimpinellifolium, I had three F2's with other tomatoes in eight plants, each radically different from the other. Going to be a good year for tomato genetics.

Quote from: William S. on 2022-05-06, 09:08:42 AM
Andrew I've been calling the strain from you Andrew's Exserted Pimpinillifolium. Any notes in its origins?

I'll keep looking for an old paper copy, but from my email requests it seems there are no pimpinellifolium requests and no history of pimpinellifolium orders from commercial seed sources. IF it was purchased it probably came from Alan Kapuler, but I honestly have no idea where I got it. I know a few of my digital TGRC request emails have been lost because they were done with my old university email address, and I don't currently have access to that. I'll let you know if i turn anything up.

As of now, can't find any records of which accession I grew and shared seeds with you william. I am pretty sure it was from TGRC or USDA, and a few numbers stand out to me, but no idea right now.

If i had to guess, I'd say LA2934 from USDA. But, it is just a guess.

On the flip side, if I were to try using the species again from scratch, these are the accessions that mention exerted stigmas and sound interesting for other reasons too:

LA3859, Large flowered, stigmas exserted 5mm
LA2540, 4-5mm exerted
LA1381, stigmas exserted to +4mm. 89L: large flowers.
LA2536, stigmas exserted 2-4 mm
LA2538, stigmas exserted 0.5-4 mm (mostly 2mm)
LA2539,  stigmas exserted 3 mm
LA1258, stigmas exserted 2-3 mm. Therefore should probably be grown in the greenhouse.
LA1606, stigmas exserted 2-3 mm
LA2535, stigmas exserted 2-3mm, flowers medium size.
LA4681, Yellow fruit, exserted stigmas,
LA4714, Medium sized iflorescences, exserted stigmas, orange anthers
LA4716, "Inflorescences medium, exserted stigmas, orange anthers, some have poor seed set
LA4718, Divided inflorescences, hairy fruits, exserted stigmas
LA4721, Exserted stigmas, peanut shaped fruits

Also, this species is not native to the galapagos islands, but there are a few accessions there if you look at the TGRC map. (LA3123 & LA2857)

There is also one outlier for S. cheesmaniae or S. galapagense which mentions it has RED fruit, a probably hybrid. (LA1408).

I hope it is LA2934 or similar as Solanum pimpinillifolium accessions other than the common ones like Everglades, Mexico Midget, Sweet 100, and Sweet Pea are uncommon and accessions from Peru have a lot more potential for rare genetics than accessions from farther from the center of tomato diversity.

My pimpinellifolium strain has fruits about 3/8" diameter. The F1 hybrids with lycopersicon had fruits  up to 3/4" diameter.

Last summer, I crossed pimpinellifolium with a self incompatible strain of [domestic X (pennellii or habrochaites)]. I'm growing out about 18 of them this summer.

Just a note: my F1 pimpinillifolium crosses I grew out in 2023 were both tasty red cherry tomatoes. I made ~3 such crosses in 2022 with two accessions of pimpinillifolium from the USDA ARS GRIN system. One of which might be the source of PH5 LB resistance and the other of which is known for Brown rugose resistance. Next year it will be fun to see how the F2s segregate.

To my understanding, once a domestic tomato crosses into a Pimpinellifolium, it's then considered to be a Solanum lycopersicum type of thing.


White Currant, Florida Everglades Currant - and others, were likely crossed with domestic tomatoes, accidentally or not.


Pimpinellifolium types usually have a trait which let's them outcross to a small extent.


Companies have thus usually only sold stable crosses.



Spoon tomato, may be a actual Pimpinellifolium.


Wild Currant Tomato From Peru, and Alberto Shatters are true Pimpinellifolium types.


But, frankly speaking. Domestic tomatoes wild ancestors are Solanum pimpinellifolium.

For some reason, they're marked as different species.


Marking something as Lycopersicum x Pimpinellifolium, seems tedious and unnecessary if the crosses are stable.


So for this topic, maybe just considering small, Currant sized tomatoes as Solanum pimpinellifolium will work, even if they're hybrids.


I'd discount them from the group, if they're something like Dancing with Smurfs. Anthocyanin colors on the fruits, usually means there's wild genetics from another species and thus definitely not pimpinellifolium.


There are a ton of Currant tomatoes online, it's probably a safe assumption that none of them are purely Solanum pimpinellifolium.


But, just calling the name, rather than "Currant" or whatever may work out well. There honestly usually isn't a big difference.



I really like the Wild Currant Tomato From Peru. Not a great name for it.


It tastes like nothing. I bite into the things, and they taste like watery shells with a tough skin. Pea sized, full of water.


Decent amounts of slightly exserted flowers.

I'd prefer to select for smaller fruit / seeds, to facilitate better crosses with other species.


I've also noticed something with the wild landraces.


There's the need of weeding out the small fruited genes, and some incompatibilities.


With them, I just need to select for disease resistance, seed size and whatever else.


Larger tomatoes also usually have bigger seeds.


So, a very exserted group of plants, and just select for disease resistances. And then also select for SI plants.

Maybe make sure they can cross into larger fruited tomatoes as well.


But yeah. I'm not sure if people here categorize the species based on origin or if any domestic hybrids get discounted as a non pimpinellifolium.

Quote from: Garrett Schantz on 2023-09-30, 05:07:01 PMTo my understanding, once a domestic tomato crosses into a Pimpinellifolium, it's then considered to be a Solanum lycopersicum type of thing.

Quote from: Garrett Schantz on 2023-09-30, 05:07:01 PMMarking something as Lycopersicum x Pimpinellifolium, seems tedious and unnecessary if the crosses are stable.

Personally I think if something is half half, it's worth noting that. Half is a lot!

Quote from: Garrett Schantz on 2023-09-30, 05:07:01 PMThere are a ton of Currant tomatoes online, it's probably a safe assumption that none of them are purely Solanum pimpinellifolium.

I noticed the seeds of so-called pimps from HRSeeds are large and so I expect them to be at least half lyc. And I reckon going by seed size is probably the easiest way of telling if a pimp is pure or not. But I did encounter a curious thing - of the 4 genebank pimps I have, one has somewhat larger seeds, not as big as lyc but bigger than standard wild species. That made me suspicious so I asked them and they at least seemed sure it was pure. Growing them out, the fruit size is consistent with the surely pure ones, but, it's the only hairy stemmed one! That increased my suspicions. So, do you guys know of any surely pure pimps that have hairy stems? I don't mean hairy like LA1777, just in the normal lyc way. Mention above of hairy pimp fruit got me thinking about this also. But I would not be surprised if it may have a bit of lyc in it, though, perhaps there really are wild pimps with somewhat larger seeds...

The Solanum cheesmaniae galapagose tomato sold by Terrior Seeds / Underwood Gardens likewise is not pure and some sort of wild x domestic hybrid. I still really like it, but they refuse to accept to post my reviews that state it is not pure.

Yeah, same for HRSeeds' 'Galapagos Island Tomato #2'. He states:

QuoteHere is the Galapagos Island Tomato #2, Solanum cheesmanii. This is another variation of the Galapagos Island Tomato. Tho there are only 2 endemic species on the Galapagos Islands, There are several variations of each species. Some of the them are natural hybrids that crossed with solanum pimpinellifolium which are an invasive species in the archipelago. This variation seems to be from the original plants on the island. Some of the tomato plants there can be decades old with wooden trunks and still produce fruits even to this day! Open pollinated Indeterminate mid season regular leaf 65-85 days.

But from seed size, fruit size and fruit shape, I'm quite sure it is a lyc hybrid. I wrote to him about several of his apparent misidentifications but got no reply. You really have to be careful with seeds being sold by people! Also while some cheesmaniae hybrids apparently taste good, like the one you mentioned, this one doesn't, in my opinion. Though his gal x lyc (listed as 'Galapagos Minor Cherry Tomato F2') tastes really nice, and has quite good fruit size! Also didn't get late blight though did crack after heavy rain (I only grew 1 so this is not a comprehensive report).Though also, many of his seeds of various types failed, seems they were crushed, perhaps either due to the way he processes them (blender?) or due to lack of care in packaging.

Some gene bank accessions probably are mixed but wild collected and carefully kept pure since accessioning. Because of gene flow with domestics before collection and accessioning.

Normal part of wild crop relatives, if near humans is bilateral gene flow between wild and domestic populations. My source for that thought is one of my favorite authors Gary Paul Nabhan. He explores the idea extensively over multiple books.

Also, it is possible that some Lyc genes were already present in some wild pimp populations before domestication.

I wonder how divergent lyc and pimp really are. May depend on the population of pimpinillifolium.

Somewhere there is or was likely a source population.

I had to re-evaluate what I thought pimpinillifolium was while growing the two wild gene bank accessions I grew last year. Their leaves didn't seem like what I thought of as typical pimpinillifolium. This could be contamination or gene flow with domestics before accessioning but it could also be variation within a diverse wild species. Lyc had to come from somewhere after all.

I agree that half Pimps are worth noting. I also think any tomato of near current size likely has a lot of pimpinillifolium or other wild tomato in its genetic background. I was very intrigued recently to learn that the heirloom tomato Farthest North bred in North Dakota is a pimpinillifolium cross. I remember speculating back in 2017 that it seems like all very early tomatoes had some pimpinillifolium like characteristics and now I know that a lot of the more recently bred in North Dakota, Idaho, and Alberta have Farthest North in their pedigrees- so probably a lot of early tomatoes with unknown pedigrees have pimpinillfolium too. I don't think that means no further crosses with pimpinillifolium are needed though because their is a lot of diversity spread across lots of accessions there containing potentially useful traits. Also most modern tomatoes have significant large pimpinillifolium and other wild species introgressions for specific resistant traits.

Yeah.

HRseeds does mention in some of his listings, that some of his Galapagos Island seed came right from the Islands.


But, Pimpinellifolium and some probable cherry tomatoes are invasive there.



They cross with back and forth with Cheesmanii and Galapagense.


Birds are reported to favor orange fruits, and so that's what they mostly eat. Many tomatoes end up becoming predominantly orange tomatoes throughout a large area as usual.

Single areas can have a ton of domestic hybrids just dropping and seeding.



I'd also assume that like William has said, this happens with Pimpinellifolium and Lyco as well.


The Galapagos Islands just happen to be well maintained and studied. Besides the whole thing with overfishing being allowed.

It occurs to me, after looking at some somewhat mysterious current and cherry tomatoes in my garden this morning, that it is certainly plausible for current size red tomatoes to arise entirely from hybridization with Solanum habrochaites or another green unpalatable species and domestic tomatoes.

Quote from: William Schlegel on 2023-10-01, 08:56:57 AMSome gene bank accessions probably are mixed but wild collected and carefully kept pure since accessioning. Because of gene flow with domestics before collection and accessioning.

Yeah that makes sense. Probably not a bad thing since it seems some of those pre-colonial landrace tomatoes they might be crossed with have maybe greater disease resistance than the European ones?

Quote from: William Schlegel on 2023-10-01, 08:56:57 AMAlso, it is possible that some Lyc genes were already present in some wild pimp populations before domestication.

That would seem to imply you don't think lyc resulted as the domestication of pimp....? I would have thought that... most lyc genes were already present in wild pimps, no? Or, do you mean some domestic traits like bigger seeds? It would make sense that maybe some pimp populations has slightly bigger seeds and those ended up being favoured by the domestication process, maybe. I guess it might also be possible that some populations underwent partial domestication and were then given up on as human populations adopted better strains from neighbours. Though in my very limited understanding, I would guess maybe some amount of crossing to domestics somewhere along the line might be more likely. Though of course I really don't know. I wonder how long the seed size increase took in the domestication process?

I've also just had a thought - have any of you experience or knowledge of breeding with Andean landrace tomatoes? Perhaps we can gain a lot of genetic diversity and disease resistance by stepping back beyond both the European bottleneck and the bottleneck of the movement to Central America by looking at those, without having to step back prior to domestication, so as to keep the larger seed size and the relative size increase that they embody? I've made some crosses with Columbianum (a domestic landrace) but didn't grow it outside so not sure how it performs with the disease pressures here, though it's said to have some disease resistance.

Here's a couple of quotes from the paper 'Exploiting the diversity of tomato: the development of a phenotypically and genetically detailed germplasm collection'. N.B. abbreviations SP and SLC are referring to Solanum pimpinellifolium, and Solanum lycopersicum var. cerasiforme:

QuoteSLC has a worldwide distribution in tropical regions, but it is native to the Andean region of Ecuador and North of Peru1. This species is found over a vast range of environmental conditions such as tropical or arid regions, sea level or high altitudes23, and it has also been collected at native markets24. It usually bears red and small fruits, but Rick and Holle25 described a remarkable morphological variability in fruits, plant habit, or leaf size and shape. A higher genetic variability has been described in Ecuadorian and Peruvian accessions1,2 due to the development of morphological diversity during a pre-domestication phase. In fact, tomatoes collected in local markets of Ecuador were morphologically classified as vintage tomato; but they have been genetically classified as SLC3. These studies and data show that SLC from Northern Peru are very close to Mexican and vintage tomatoes. Despite that, Amazonian SLC has not been used frequently for tomato improvement as opposed to SP. Furthermore, SLC has been characterized as a valuable genetic source for abiotic and biotic stresses, such as moisture-tolerance26 or resistance to root rot caused by Phytophthora27; traits related with the global climate change and sustainability challenges currently facing agriculture.

Perhaps Peru and Ecuador could be the most promising source?

QuoteGenetic variability
As expected, the highest level of diversity was found in Peru and Ecuador for both SP and SLC groups2,3. Rick and Fobes1 described that variation in SLC depended on its geographical origin, being SLC from other countries less variable than SLC from these regions. The analysis within the SLC group also revealed a considerable decrease in the number of SNP variants detected in SLC Mexico. This is in agreement with the loss of variability that took place during the migration to Mesoamérica2,3,41. The detected 37,974 SNPs labeled as high impact show that this collection may be an interesting source of new alleles.

I tried searching for LB resistance in Andean landraces with no luck. But I did find the paper 'Assessment of Tomato (Solanum lycopersicum) Landraces for Their Agronomic, Biochemical Characteristics and Resistance to Phytophthora infestans'. These are landraces from, forgive my copy and paste: AU−Austria; FR−France; GR−Greece IT−Italy; RO−Romania; RU−Russia; TH−Thailand.

From the supplementary table they have some with 'high' resistance to LB with fruits of 90~95g weight, and with 'very high' resistance up to 23g.

Quote from: William Schlegel on 2023-10-01, 05:37:29 PMIt occurs to me, after looking at some somewhat mysterious current and cherry tomatoes in my garden this morning, that it is certainly plausible for current size red tomatoes to arise entirely from hybridization with Solanum habrochaites or another green unpalatable species and domestic tomatoes.

One reason I was crossing pimp x pen was the idea of making small cherry tomatoes only by combining wild species, avoiding lyc altogether. I could imagine various complex combinations using pimp, chm, pen, gal, and che. I'm now growing out:
pimp x pen
pimp x arc
pimp x chm
che x chm
gal x pen (waiting to germinate)
gal x chm

Already made cross attempts between some of these amongst each other and back to gal and che. And might have some gal x hab crosses coming if my cross attempts succeed.

Two thoughts on that though:
1) The only parents among those that impressed me against LB was arc.
2) It could be handy to have at least some lyc in the mix to gain larger seed size. I'm growing out various lyc crosses such as lyc x gal (reciprocal), lyc x arc, lyc x chm, lyc x che (reciprocal)... and do plan on crossing those with the above also. It could be nice to bump up the seed and fruit size that way whilst still having only 25% or even much less lyc.
3) It could be worth using ph-2 and ph-3 homozygous lyc to cross into these, since even with such glorious diversity, it's not worth much if they don't have sufficient LB resistance. I am now growing such lyc for that purpose.
4) If there is an Andean landrace lyc that has sufficient LB resistance, that could be a nice way of gaining seed and some fruit size, whilst completely bypassing the double bottlenecked genepool of mainstream tomatoes. Though that might be more of an intellectual pleasure than anything else, if one is to end up with anyway such a small percentage of lyc, and the increased fruit size available from crossing with more modern tomatoes might outweigh such concerns. So perhaps a large fruited ph-2 and ph-3 homozygous lyc would end up being a better choice.

I do think Lyc evolved from pimp. I also think I was defining pimp too narrowly. The two accessions I got from the gene bank had leaves more like lyc than what I had previously thought of as pimp.

To speculate a bit wildly. A lot of variation is possible in a species complex with a dozen species in it.

So how did lyc come to be? How did the variation in pimp come to be?

The answer could vary depending on the tomato accession. 

The variation in lyc you just mentioned in South America is intriguing.

Ah yeah, that makes sense.

That bit about Amazonian SLC diversity is quite interesting.

The diversity in tomatoes is enormous.

You've made tremendous crosses.

Believe I mentioned the idea of crossing only wild species as well


Seems like it would be easier to just focus on unique tastes, SI and disease resistances rather than making groups of plants and working on making lines with large fruits or whatever else.


Plus people have already noticed the problem, where new accessions being moved over in large numbers, to Wildling or other groups, isn't always ideal and can have issues with some goals.



Glad to see that someone else thought of the same idea.


Orange Peach is interesting. Garden Peach and Wapsipinicon Peach, all have fuzzy skin.

If I remember correctly, they're originally from Peruvian varieties in the mountains.

That's different from Cocona, from similar regions and whatnot. Garden Peach can also apply to Cocona.


The fuzz, seems to be different than the gene responsible for Woolly Kate, and other "fuzzy tomatoes."

Two of those tomatoes, have a cream / white, to a yellow coloration to them.


I've also found them to be fairly disease resistant. One "originated" in 1890 or so. Yeah. Rather old.

Granted there are different "strains."


I'd have to get into older stuff that I saved. But there are reports of fuzzy skinned orange / yellow tomatoes in the mountains.


I've taken a guess, that with the disease resistances, "spicy / fruity" flavors, cream / yellowish skin, fuzzy skin and the disease resistances - that the Garden Peach could be crosses with Solanum habrochaites.

It's well known that bees will carry pollen, some distances and that Peruvian varieties tended to be exserted to some extent.


I'd assume that Garden Peach and things, were stabilized or messed around with a bit.

I also have no evidence to support the claims.



I will agree that looking into Lyco types from South America, could prove interesting.


One big negative, is that modern varieties are bred to have less diversity and be more uniform. South America was hit pretty hard with that.



Go 100 years back, and you'd probably find a ton of cool landraces.


Early domestication reports, and complaints mention that tomatoes outcrossed a lot.


Europeans really wanted uniformity.


Small villages and the like, probably have the most diversity.


Teosinte crossing into corn was seen as a good thing by Native Americans. I'd imagine that some South American tomatoes which had exsertion, occasionally took in Pimpinellifolium genes or other things.


I'm unsure if they'd see that as a good thing as well, or not. Hybrid vigor would probably be very nice - immediately and be absorbed into a landrace.

Thanks William. 69 successful interspecial tomato crosses (of which I have processed the seeds) so far this year, 29 of which were with wild females, 14 of which were wild x wild. And many more crossed fruits ripening....

Quote from: Garrett Schantz on 2023-10-03, 01:36:38 AMSeems like it would be easier to just focus on unique tastes, SI and disease resistances rather than making groups of plants and working on making lines with large fruits or whatever else.

For sure the fewer things one selects for, the easier it is. But still, fruit size is important for me. I would not want to finish up with fruits only the size of pimp or gal, they're tiny! And I don't mind some populations with cherry sized tomatoes but I'd for sure want some that are bigger.

Quote from: Garrett Schantz on 2023-10-03, 01:36:38 AMPlus people have already noticed the problem, where new accessions being moved over in large numbers, to Wildling or other groups, isn't always ideal and can have issues with some goals.

Would you like to elaborate?

Quote from: Garrett Schantz on 2023-10-03, 01:36:38 AMOrange Peach is interesting. Garden Peach and Wapsipinicon Peach, all have fuzzy skin.

Any reports on how it (or those other fuzzy ones) does with late blight?

Quote from: Garrett Schantz on 2023-10-03, 01:36:38 AMOne big negative, is that modern varieties are bred to have less diversity and be more uniform. South America was hit pretty hard with that.



Go 100 years back, and you'd probably find a ton of cool landraces.

I think there are still many out there, and also in genebanks.

Quote from: Garrett Schantz on 2023-10-03, 01:36:38 AMI'd imagine that some South American tomatoes which had exsertion, occasionally took in Pimpinellifolium genes or other things.


I'm unsure if they'd see that as a good thing as well, or not. Hybrid vigor would probably be very nice - immediately and be absorbed into a landrace.

I would guess they would select against them, due to fruit size reduction. Though I would not be surprised if people and/or villages would grow multiple landraces, like they do with potatoes or in other places, rice etc. So I would guess that's where more of the crossing would be. But anyway there'd be a lot more diversity in their landraces as a whole, and should still be now even if not as much as before.

Yeah, but it seems like they didn't select against Exserted traits, till some new farming practices made their way over.

A lot of varieties also went to different villages and sometimes replaced other ones.


Gene / seed banks probably started a bit too late, to have the best landraces.



Most seed banks also don't note certain odd qualities of fruits or Exserted traits and things. It's usually disease resistances and whatnot.



The only main issue with Wilding, is that as lines progress - people are looking for larger fruits.


Eventually, they'll end up with a line of larger fruited plants.


They'll also probably select for things that lack fertility issues.


This means that some relatives, may not be able to just cross over ad readily as before.

And, while it's possible to set aside a large group of Wilding plants and the like, to cross with new things, large fruits would need to be reselected for. Over and over again, as new things are added to the pool.


Any interesting flavors, would be gone. Fruits may all become very watery.

Or sour.



With keeping a population of smaller seeded / fruited Pimpinellifolium crosses, this could enable crosses with smaller seeded relatives.


Flavor could be gradually worked on.

Then you'd move that over to something like Wildling once you have a very interesting population.


Rather than increasing fruit size or focusing on taste / flavor, you'd just work on disease resistances, and working on making lines that can cross readily with even more species.



With Wildling, most people will immediately want to select back towards larger fruits, tastier fruits and whatnot.

Adding in some Pimpinellifolium or other things, these can mess with Exserted traits.



I don't think people do it on purpose. But more recent crosses have seemed like an immediate push or want for larger fruits and other things - immediately, resulting in a lot of backcrosses to restore wanted flavors and size.



It's not so much an issue at the moment.


But, I've noticed that some Habrochaites accessions or other species already in mixes, which have resistances or traits that others don't - or things that may seem redundant, they're being seen as a pain to add in just for one thing or whatever else.


If we focus on a line with smaller seeds / fruit and try making a stronger plant, more resistances to whatever.



People may feel less inclined to backcross things into oblivion.


I feel like a lot of earlier crosses of Habrochaites and things, a lot of genes were lost due to climates not favoring some accessions or species.

Some of that is being worked on now.



I do feel that a smaller fruited line, to compliment an eventual very exserted line of Wildling, would be of interest.


Every now and again, just cross that population, back into Wildling or have them growing some distance from each other.


I feel like labs selecting put singular genes and flagging those, doesn't show the entire picture of what gives a plant resistances.


If you look at older hybrids, which were backcrossed over and over again in order to be resistant, they're still around.


Most studies show that a disease or pest resistance, is usually made up of a chain of resistances.


That's also why I've been interested in Solanum pimpinellifolium, despite it being used somewhat heavily in breeding.


Older hybrids / heirlooms lasting longer than newer ones, isn't a good sign.

Modern plant breeding of finding specific genes in labs and deciding that's entirely what makes a plant resistant, and selecting for those genes in plants using markers.


A lot of other genes get lost.




Garden Peach and Wapsipinicon Peach, both seemed Late and Early Blight resistant when I grew them.

I wanted to see if they were the same varieties or not. They're somewhat different in flavor and fruit size.


I've read that they may not be as resistant to some newer strains of blight, or it depends on the year they're grown.

Selecting for larger seeds and some other traits in a population, will likely mean that Wildling may have issues crossing into some other species or back into whatever.


There's also probably some flower issues and other small things.



A population that's entirely meant to act as a bridge and just take up new lines, without worrying about muddying anything up, may be interesting.


People do still have older seed saved, and have been regrowing older lines and mixing them up again every so often, but yeah.


Eventually there may be issues. Especially for those wanting to backcross into Habrochaites or other species as the mother.


Their smaller seeds and some other traits and things, may act as barriers. Seeds are akin to something close to a representation of embryos.

Pollen size and other factors are also a thing. Flower structure can play a part as well.

Wildling or derivatives may eventually end up with larger flowers and pollen structures and things that are nearly identical to Habrochaites. That's great.


Habrochaites is more likely to be a favorite to bees than domestic flowers, usually has more pollen and food / more attractive flowers, simply due to being SI.


There is nothing wrong with Wilding, it's great and it's a needed step in making edible lines of outcrossing tomatoes.


If we make a seperate line, that's eventually exserted - still edible and whatever, and just add new things to that - let others mix the line into their Wilding and select what grows the best for them, that population would have a ton of genes - non bottlenecked ones, and we'd be able to add other species and things to it every so often.


A Currant or cherry sized tomato may work if we find enough small seed genetics. Even superficially small seeds may work. Some are small due to certain factors or other traits.


Seedlings with larger seeds, usually have a larger boost than the others. And hybrids also tend to be weaker in the F1 or whatever.

So, most of us select for larger seeds because they're easier to plant and they usually give stronger seedlings.



The mentioned sort of line or group, may work well for innermixing Pimpinellifolium.



It's just been a back burner sort of idea on my part.



I'd like to cross Purple Smudge, Payette, Double Rich, Burnley Bounty and things like the "Peach" tomatoes into an exserted tomato, just because I feel like they'd be very interesting inside of an interspecific line.


Some people have tried using those as bridges, but with the Peruvianum ones, those usually have multiple barriers inside of them.

Burnley Bounty is frankly day length sensitive. Purple Smudge has anthocyanin from Solanum peruvianum and both are pretty disease resistant.


Double Rich and Payette, seem to have been victims of a ton of backcrosses to create something favorable. Double rich didn't get it as bad as Payette, I think.


These also may have certain S allies that Peruvianum gas.




But, this is about Pimpinellifolium. I believe that looking for accessions or things with odd traits, from Peru or wherever, may be very interesting.

Quote from: Garrett Schantz on 2023-10-03, 02:02:26 PMTheir smaller seeds and some other traits and things, may act as barriers. Seeds are akin to something close to a representation of embryos.

Seeds are embryo + endosperm + seed coat. The larger endosperm is very useful for the initial growing stage after germination. I have not noticed any correlation between seed size and ease of crossing. This is based on crossing things like... lyc pimp che gal and chm all to these mothers: lyc pimp gal che. Also attempts of crossing per chil and arc to lyc pimp and gal, which only gave successful results with arc, to lyc and pimp but took ... was at least dozens, maybe even 100 or so attempts to get the very few successes, only 1 of which was successful with pimp though even with that one I am not yet certain if it's a definite arc cross, I will have to wait for ripe fruit to be more sure.

Quote from: Garrett Schantz on 2023-10-03, 02:02:26 PMHabrochaites is more likely to be a favorite to bees than domestic flowers, usually has more pollen and food / more attractive flowers, simply due to being SI.

I am starting to think that colour might be very important. I saw much more bee activity on per chm and arc than I did on Wilding (and other related) plants that had bigger flowers that we would think of as 'more showy'. When I crush the per flowers I see the vibrant colour on my fingers. I would guess selecting for such colour (perhaps there is a filter one could look through to identify it) might turn out to have more impact than mere flower size.

Quote from: Garrett Schantz on 2023-10-03, 02:02:26 PMBut, this is about Pimpinellifolium. I believe that looking for accessions or things with odd traits, from Peru or wherever, may be very interesting.

Yes if I knew then what I knew now, I would have specifically selected explicitly late blight resistant accessions of pimp. But, if I could get that resistance from pre-Columbian landraces, I would definitely go for them rather than pimp.

I grew Solanum chmielewskii before.

It's flowers were exserted.

I also noted that they were glossy / shiny, which indicated more bee food was present on them.


I believe that issue of seed sizes being a factor in crosses, is from one parent to another.


Large has trouble going to small or maybe it's the other way around.

That's more pre-embryo stuff, but after fertilization there can be issues.

The main issue with ease of crossing with seed size is usually with larger seeded domestics.


I'm interested in potential crosses from outside of the clade, potentially selecting for smaller flowers or growing something like S. nigrum next to an interspecific group.


That's a stretch goal.


But, any interspecific which may have barriers or issues - I'd prefer to have the least amount of incompatibilities, flower structure wise and whatever else.

Quote from: Justin Jardinier on 2023-10-03, 12:22:50 PMThanks William. 69 successful interspecial tomato crosses (of which I have processed the seeds) so far this year, 29 of which were with wild females, 14 of which were wild x wild. And many more crossed fruits ripening....

A very, profoundly, successful tomato year. F2's will be spectacularly interesting.

Quote from: Garrett Schantz on 2023-10-03, 03:46:03 PMgrew Solanum chmielewskii before.

Yeah I really like chm flowers! Did you make any crosses with it?

Quote from: William Schlegel on 2023-10-05, 06:41:04 PMA very, profoundly, successful tomato year. F2's will be spectacularly interesting.

I really appreciate your encouragement William, it means a lot. I'm trying my best to grow out the most important F1s now to have the F2s ready for next year. I have a few F2 seeds already now for some of them (though most F1s are just seedlings so far), and some double crossed fruits nearly ready to harvest, and have some homozygous ph-2 and ph-3 domestic seedlings growing which I plan to cross most of the F1s with also for my wild hybrid LB resistant project. I should probably be making mentor grafts to LA1777 also to see if I can bring over some traits non-sexually... any ideas if air layering might work with hab? (Tie a bag of soil to a branch to make roots grow, for making a cutting, in case this is a new term for anyone reading this like it was for me!). Would save me digging up the whole plant.

Today one of my arc crosses has its first open flower (the last of the arc crosses to start flowering). I found this one quite interesting because of the variation in leaf shapes. Here's how the lower leaves look:
IMG_0711.jpg
Try to ignore the surrounding peruvianums! It's the leaf in my hand. Quite smooth edges.

Two leaves up and we have this, very serrated!:
IMG_0712.jpg 

Here are the flowers - again it's just the ones indicated by my hand - below my little finger that's peruvianum:


Not sure if this is normal but I haven't noticed it with others. At some point it just seemed to switch from smooth to serrated leaves! I'll be working with its pollen today...IMG_0713.jpg

Unfortunately no. I grew them indoors when I had them. I'm fairly sure the place that I got them from, got them from overseas.

So I like growing things indoors, prior to any outdoor growing.


I didn't have anything good to cross them with. Mostly wanted more seed.


Which I lost my seed during the move.

Also grew Chilense that year.


I got these seeds.


https://www.hrseeds.com/product-page/wild-currant-tomato-from-peru

https://www.restorationseeds.com/products/alberto-shatters-tomato

https://www.hrseeds.com/product-page/heirloom-reviews-woolly-currant-tomato

https://www.hrseeds.com/product-page/woolly-mammoth-tomato (this one also seemed neat but I didn't purchase it)

https://www.hrseeds.com/product-page/arcanum-pink-cherry-tomato-hr


Plus, Orange fleshed purple smudge tomato, Sart Roloise, Woolly Kate, Fuzzy Peach,  Garden Peach and Wapsipinicon Peach.

And a Habrochaites.

I may have some Peruvianum seed still lying around somewhere.


Fuzzy Peach is sold by Restoration Seeds. It could be related to Wapsipinicon Peach and Garden Peach.

BakerCreek sells a variety called Orange Peach, described as a chance cross.

The name and the fuzzy fruit, to me indicates that it's possibly a hybrid between something else with one of the other Peach tomatoes. I didn't order that one.

I'm unsure if Fuzzy Peach is just another name for Wapsipinicon Peach or Garden Peach or if it's another strain.



I've become interested in growing out some woolly / fuzzy tomatoes again.


One of the Galapagos tomato hybrids, seems to have woolly fruits. Likely different genes than the ones found in Woolly Kate - those woolly ones are supposedly originally from a mutation at some point.


I probably should've sought out some carrot leaf foliage type, plus Lutescent, Cherokee Tiger Large and variegated tomatoes as well. There's also Stick tomato.


Some types considered to be oddities, mutants and things.



I should be able to properly review some Pimpinellifolium types in the coming season.


And compare them.


For one, crossing Woolly Kate with something like the Galapagos tomato hybrid.


Or the Garden Peach with Woolly Kate or something.

I'd prefer to cross Garden Peach and things, into an Exserted population.

I'd like to try Exserted Tiger, just because.


Then I'll try and work the three Peach tomatoes, into a grex.

Then maybe I'll get to crossing them into a Woolly Kate x Furry Galapagos tomato x Domestic.

I'm interested in seeing whether or not crossing these will give me hairier tomatoes or if they're caused by similar genes and it'll be one or the other.


Garden Peach and things, feel akin to a nectarine or peach. The hairs sorts of dissolve in your mouth.

You could also just wash them off before usage.


But their fuzzy gene only seems to affect the fruit.

I can't remember if the Galapagos tomatoes give out furry fruit and leaves tied to the same gene.


If I can find a bunch of selections of Garden Peach, and other domestics that are of interest - I'd like to combine them into Promiscuous lines.


For one, different variations could mean the originals weren't stable. Or that there were multiple types.

Or that they crossed with other tomatoes.



Crossing Burnley Bounty and Purple Smudge into a Promiscuous line is also still on a to do list.

Plus, Sart Roloise.


Galapagos tomatoes from the furry type, supposedly also impart citrusy tastes and things into their offspring.


So, if I'm crossing it over into Woolly Kate, I could probably try and select for some nice flavors on top of the fuzzy fruits. Plus the fruit sizes could be worked to be Woolly Kate's size.

Not to mention the anthocyanin.



Burnley Bounty, Purple Smudge, HR Arcanum - I'd cross those into a Promiscuous line over and over again.

Until they're all fully mixed over and have different gene flow in a population.

I may just toss Sart Roloise in, and select for its flavors, fruit color and size. Plus the anthocyanin - Purple Smudge should impart Peruvianum anthocyanin, which is supposedly from a different gene than other anthocyanin types.


The Arcanum cross, I'd likely mix into that group and a planned Pimpinellifolium grex with Exserted flowers - maybe mix in Habrochaites as well.

Purple Smudge and Burnley Bounty likely have some fun genes which could mix well, and aid in any possible Peruvianum crosses.

Crossing over an Arcanum hybrid, could also up the success rate of crosses in either direction.

Sacred Succulents claims to have Lycopersicon chilense, assuming that is a valid species.

It's probably considered to be Solanum chilense by most botanists.

I think that many "sections" and groups should become full on new genera.


Prunus and Malus are as probably as closely related to each other as some Solanum species are.

I've asked this before in the wider context of crossing with wild tomato species. So, sorry for the repetition. But in case this more specific question might stimulate some response: Has anyone done reciprocal crosses with lycopersicum x pimpinellifolium / pimpinellifolium x lycopersicum? I would be very interested to hear if any trend of difference between the direction of the cross was noticed in the descendants, in particular anything relating to size, earliness, yield, and disease resistance.

My Pimp/Lyc cross happened on its own and I just assumed that the pimp was the mother. I guess I thought that because of the foliage and the small fruit size. Whatever it crossed had much larger fruit, much larger. The pimp flowers are very closed though, so maybe it makes more sense that a little pollen got out, rather than some getting in. This year I might try to cross some of the descendants back onto a big potato leaf beefsteak and see what happens. 

Looks like I have nine new pimps to make crosses with in 2024. I'll try to make some of them with the current tomato as the mother.

Quote from: William Schlegel on 2024-02-19, 08:17:49 PMLooks like I have nine new pimps to make crosses with in 2024. I'll try to make some of them with the current tomato as the mother.

I have some pimps to cross with too, and was considering only using them as mothers. Since they give so many fruits, and should ripen a lot faster than the giant fathers I have planned. So long as there is no drawback to using them as mothers, I would rather do it that way for those reasons, plus the potential benefit of having more diverse cytoplasm in my populations. But if there is a known drawback, I'd love to know about it.

I read a paper on crossing a pimp with a giant tomato, and they went into weights of offspring. Unfortunately, they only used the lyc as mother since it was 'easier'. Pretty unfortunate for my line of enquiry! I think working with pimp flowers is actually pretty easy once you get used to it.

I'm kind of HOPING for a pinp/lcy cross this coming spring (or, more accurately, a pimp-lyc/lyc cross.) As I have mentioned, I have always wanted a current type tomato that is green when ripe (currant type because smaller fruited tomatoes produce a lot more reliably for me here than normal to larger sizes ones.) So this year, I am hoping that some pollen from my White Currant Tomatoes (thing pimp-lyc parent) mixes with the Opening Minded plants a medium to large sized "deceptor" green (my term for any green when ripe tomato that has NO yellow, pink, red or other color pigments as secondary tints, and also no yellow skin trait.  I.e., a tomato you can't tell is ripe without feeling it.), or vice versa.   

After some digging, I have found the paper The role of small RNAs on phenotypes in reciprocal hybrids between Solanum lycopersicum and S. pimpinellifolium:
https://bmcplantbiol.biomedcentral.com/articles/10.1186/s12870-014-0296-1#MOESM1

The do give fruit weight difference between the direction of the cross. However I see what I consider some flaws with this paper:
- They used Micro Tom as the lycopersicum parent. It is a highly unusual tomato, including it being a dwarf, and having extremely small fruit.
- They examined only the F1, not F2 or beyond. I think seeing the segregation of sizes in F2 would be much more helpful, and especially if the lyc parent were an ordinary tomato or even better, a specifically large fruited tomato.
- They gathered their data from only 3 plants of each cross, and they state "Fruit traits of four types were observed at the fruit maturity. The data are the mean of three measurements and were subjected to analysis of variance (ANOVA) [47]." It's unclear to me if this means 3 fruits per plant, or, if we take what they are saying literally, merely 3 fruits in total per cross, i.e. one fruit per plant. The latter would be a very small data set, which I would be quite cautious to rely on. Especially since in the photographs they provide, there looks to be perhaps on average more fruit size variation within category than between category.
- Their display of fruit size is on a bar chart with large increments which we therefore cannot read the values easily.

That being said, in the F1, it looks from their bar chart that their lyc x pimp had about 17% lower fruit weight than their pimp x lyc had - a perhaps surprising result. I hesitate to rely on this information, but it at least gives some encouragement for using pimp as mother.

They go into other data the practical application of which is beyond my understanding. Here's a quote formthe abstract:

QuoteResults:
 Reciprocal hybrids between Solanum lycopersicum cv. Micro-Tom and S. pimpinellifolium line WVa700 were generated. Significantly different phenotypes between the reciprocal hybrids were observed, including fruit shape index, single fruit weight and plant height. Then, through the high-throughput sequencing of small RNAs, we found that the expression levels of 76 known miRNAs were highly variable between the reciprocal hybrids. Subsequently, a total of 410 target genes were predicted to correspond with these differentially expressed miRNAs. Furthermore, gene ontology (GO) annotation indicated that those target genes are primarily involved in metabolic processes. Finally, differentially expressed miRNAs, such as miR156f and 171a, and their target genes were analysed by qRT-PCR, and their expression levels were well correlated with the different phenotypes.

Conclusions:
This study showed that the profiles of small RNAs differed between the reciprocal hybrids, and differentially expressed genes were also observed based on the different phenotypes. The qRT-PCR results of target genes showed that differentially expressed miRNAs negatively regulated their target genes. Moreover, the expression of target genes was well correlated with the observations of different phenotypes. These findings may aid in elucidating small RNAs contribute significantly to different phenotypes through epigenetic modification during reciprocal crossing.

I also found this paper, Gene interaction, environment and hybrid vigour - Dan Lewis - 1955. It doesn't go into fruit weight, but does say this, indicaing benefits of using lyc as mother:

QuoteThe parents used are inbred lines of L. esculentum var. Ailsa Craig, the cultivated tomato, and L. pimpinellifolium, a wild species. They are closely related, pro.2 rducing hybrids and F 2 generations with full fertility. The hybrid shows marked heterosis in height and size of plant (Whaley 1939). The reciprocal hybrids differ in their degree of heterosis; the hybrid with L . esculentum as the female parent is more vigorous than the reciprocal. The cause g of this reciprocal difference will not be enlarged upon except to say that the F2 generation from the E x P hybrid segregates plants comparable in vigour with the J2 Fx and more vigorous than the segregates in the F 2 from the reciprocal cross. Thus the reciprocal difference is carried into the F 2 generation, and is presumably due £Ti to an interaction between genes and cytoplasm.

These parents and hybrids show marked heterosis in fertility under adverse o >•conditions. When grown during winter in England both parents produce flower ^ buds which abort when young. The hybrids, and in particular the E xP, on the ^3 ' other hand, produce flowers, fruits and seeds under these bad conditions. The o i results given in table 7 were obtained from plants grown in a greenhouse in the winter of 1951 to 1952; a half of each type were given 6 h of extra light from ^ 1fluorescent tubes, the other half had the natural daylight.

Both hybrids set fruit under the two lighting conditions, and on all inflorescences, 1 the E xP hybrid sets between two or three times as much fruit as the reciprocal in 1 i the first inflorescence. The parents do not set in the natural light, and set only about 10% with the addition of the artificial light. 'r' The type of gene interaction causing this heterosis in fertility under adverse conditions was determined from the results of selection in the F 2 and subsequent : generations. Lines have been produced which with regard to winter fertility are intermediate between the best Fx, ExP, and the parents. Thus, under the extreme 1 V i environment this heterosis would appear to be mainly due to the action of complementary dominant genes. It should be pointed out that at the same time as the selection was made for winter fertility, breeding and selection for the large fruit size of L. esculentum was practised. This would impair the efficiency of selection for winter fertility.

Source: https://royalsocietypublishing.org/doi/10.1098/rspb.1955.0044

The paper Fruit quality and DNA methylation are affected by parental order in reciprocal crosses of tomato might be interesting but is behind a paywall:
https://www.researchgate.net/publication/344814992_Fruit_quality_and_DNA_methylation_are_affected_by_parental_order_in_reciprocal_crosses_of_tomato

I'm going to try many crosses with pimpinellifolium. I also thought that using it as a mother would somewhat speed it along because of the small fruit ripening faster. I'm going to be trying crosses both ways. We'll see how it goes.

I sowed this year solanum Humboldtii thinking it was a real wild species but after searching it seems its a pimp or a cross between a pimp and a domestic. Only 1 plant showed exserted flowers. The plants vary with si and the one with exserted flower is si.

I planted a lot of old seed from my pimp crossed tomatoes in a good sized and very crowded patch. The result was the discovery of four new ones that all have amazing flavor. They are all very, very sweet.
1- is bright yellow with fruits about the size of a marble or a little smaller, but still twice the size of the pure currents that grow wild and much better flavor.
2- is the same as 1 except it's red.
3- is red and also the same flavor wise but larger
4- is unlike any I've seen before. It is like 3 except it is very, very pale yellow. I've never seen a tomato that color or tasted one with its flavor.

Over the last several years lots of variations have showed up and most have been very good but these four all stand out.

As a rule, for the last years and still, any larger ones, the biggest about the size of a ping pong ball or any oblong or pear-shaped ones were not nearly as good. I'm mostly relied on volunteers for the last years too. Next year only these four will be planted and in abundance. All volunteer tomatoes next year other than potato leaf will be treated as weeds.

I bad-mouthed Sungold, saying it was a spitter in comparison to any of these, but I found the tag on that plant, and it was Matt's Wild Cherry, not Sungold. My apologies Sungold, tuff luck Matt. I'll test Sungold next year.

My tomatoes from my deliberate current tomato crosses of two years ago are doing pretty well. I diluted some of then down to 1/4 last year. Looking forward to recovering some larger sizes next year from the diluted ones as it is a lot of cherry tomato sized tomatoes. I also have not recovered a lot of real tiny ones.

I would like to cross mine with some bigger ones too, if I ever gain the patience and skill to do that. Because of the flavor though I want next year to just increase my supply of their seeds. Also hope they are far enough along from the original cross that they are stable, since some of the seeds were pretty old, they might be close to the original cross. I guess as long as the flavor stays it won't matter if color or size changes in some of them next year.