Solanum pimpinellifolium Currant Tomatoes

[Garrett Schantz]

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.

[Justin Jardinier]

Their 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.

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.

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.

But, 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.

[Garrett Schantz]

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.

[William Schlegel]

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....

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

[Justin Jardinier]

grew Solanum chmielewskii before.

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

A 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:

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!:
 

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...

[Garrett Schantz]

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.

[Jeremy Weiss]

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

[Garrett Schantz]

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.

[Justin Jardinier]

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.

[reed]

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. 

[William Schlegel]

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.

[Justin Jardinier]

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.

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.

[Jeremy Weiss]

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.   

[Justin Jardinier]

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:

Results:
 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:

The 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

[Kadence Luneman]

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.