How wild are other people's wild crosses?

Adaptation Projects Tomatoes
21

Interesting, I thought that xenia effect was just an effect from a cross that was discernable in the F1. Not that the technical details really matter to me, I’m not a botanist or geneticist, I just go mostly by what I see and taste.

Discussion of seed size caught my attention. One of my favorite tomatoes that I call Utah Heart because I got it from Joseph years ago and it is a big oxheart type. Anyway, it has very small seeds. I mean as small or even smaller than my current tomatoes. It isn’t any more difficult to germinate than any others but when planted at the same time it consistently sprouts about a week later. It also has comparatively few seeds to any other large tomato I’m used to.

On thinking more about the original question, I guess most of my crossed-up tomatoes are 50% wild. 50% pimp and 50% domestic but they showed up on their own so I that’s about all I know.

I wonder about these somewhat romanticized tomatoes that I hear about, like Mat’s Wild Cherry and based on what I see in my own cherry tomatoes I have to suspect that maybe about all of them are actually pimp crosses. They apparently cross fairly easily; the results taste fine or better, and at least in my experience they are quite tolerant of about any type of stress.

22

I’ve seen seeds sold as pimpinellifolium or pimp and they were maybe smaller than domestic tomato seeds but bigger than things like peruvianum, pennellii etc. Then I’ve seen definitely pure pimp seeds, several different accessions, and they were the same size as the other wild species (maybe only some Galapagos ones were smaller, though again there are many impure Galapagos ones sold as ‘pure’ but clearly have domestic heritage due to seed size). Are the ones you’re talking about, like normal wild species’ size?

Ah yeah, with pimp che and gal I would expect we can have tasty tomatoes with a higher percentage much easier, since at least che and pimp can be easily eaten. Though I don’t personally like any of the pimps I’ve tasted. I’ve ben using pimps for crossing to green wilds, taking advantage of their smaller styles, though you’ve now inspired me to try crossing to a fat domestic just to see how that goes.

I was kind of assuming all cherry tomatoes or most, have pimp in the mix. Though I never checked… maybe someone here knows?

23

I’m not sure, I read somewhere that the popular cherry tomato “Yellow Pear” may be an extremely old variety- like ~300 years though don’t quote me on that as it is from memory only. I think some cherry tomatoes may date back to domestication history itself. Chiapas Wild – Native-Seeds-Search Like this Chiapas Wild accession from Native Seeds Search which they identify as Solanum lycopersicum var. cerasiforme

Also, if we consider domestic tomatoes to be domesticated Solanum pimpinillifolium then one way to look at domestic tomatoes in general, particularly given their narrow genetic diversity in true heirlooms, is as a single mutated accession of Solanum pimpinillifolium.

I recently read “Livingston and The Tomato” and in the version they included a list of tomatoes likely available at that time in the late 1800’s and red and yellow current tomatoes were available.

I found the story of Farthest North where the famous tomato breeder Yeager crossed a current tomato with Bison to get a very short season cherry to be of particular interest and is a 1934 release. Farthest North Tomato Seed - Heirloom, Open-Pollinated, non-Hybrid Victory Seeds® – Victory Seed Company

I’ve long suspected many of the short season red tomatoes bred for the North have some pimpinillifolium in their ancestry and Farthest North could go far towards explaining that both as a methodology other breeders may have copied and as germplasm other breeders may have utilized for subsequent crosses.

So of course, I bought a packet of this antique pimpinillifolium cross Farthest North and even before I’ve tasted a ripe fruit I have several green crosses with it hanging on my vines.

I made two crosses with two different true USDA ARS-GRIN Solanum pimpinillifolium accessions last year and the green fruits of the F1’s do look about cherry sized. I’ve been making crosses with those crosses aggressively for a couple of reasons- one of them being that it should be easier to recover the traits I like from a 25% parentage.

24

I’ve never seen seeds from any wild species. Just comparing to domestic tomatoes, the pimps and for the most part, their crosses are little bitty things, not much bigger, if at all than the head of a pin, and there are lots of them. All other tomato seeds I’ve ever seen except the UH are much larger.

25

The closest thing to an heirloom tomato in my climate is a variety named DX52-12, which was the Cambell’s Soup variety. It descends partially from pimpinellifolium. It got selected for the next valley over, that enjoys an extra 30 days of frost free weather.

I used to grow a mix of red and yellow pimpinellifolium, but the yellow died out, because it took two weeks longer to germinate than the red, and in my climate two weeks matters a lot!

26

wild-tomato-seeds

I found interspecies hybrids when planting this seed marked “Xenia?”.
Brad-xenia

2 Likes
27

The link in @WilliamGrowsTomatoes post describes that tomato as “For a cherry-type tomato, the plants are manageable in size, allowing them to be container grown if necessary, yet they are still quite productive.” I think that’s interesting because I discovered by accident when some Pimp-cross plants I grew to sell but didn’t sell just laid around in the cell packs for a long time.

They got tortured by repeatedly drying out and ended up getting maybe a foot tall, but they still continuously made tomatoes. One of those plants, in the ground, especially if you tend to it might take over the world if fall frost didn’t kill it.

Based on observation of mine and reading all the marketing descriptions and forum posts I’m becoming more and more convinced that that there a LOT pimpinellifolium derived and crossed tomatoes in the world.

1 Like
28

I grew 4 or 5 pimps in a 17.8cm pot indoors, they grew well, plenty of flowers and fruit.

I’m also growing even full domestics in beer cans using Kratky method. Like 330ml cans, the small cans! Obviously don’t get much fruit but it’s handy, I can make multiple crosses but the whole process goes quickly and it means I can grow in a small space. I do have plants outside too, but have several species and many accessions growing indoors in cans. It’s a pain to keep refilling them in time. But by the looks of it I should easily get F2 seeds before the end of the year, having started early this year, and I could even have F3 seeds in time for next season. This has been my ‘speed breeding’ attempt. I don’t think it’s too useful for making F3 since I’d really want to plant out F2 en masse outdoors (both due to the huge space it will require and also since I must select them for local outdoor conditions), but for making many F1 and F2 and also crossing different F1s, this seems a great way of making a hybrid swarm in a single year, giving a massive shortcut for starting the landrace method. Just within maybe 4 square metres or so I’ve made so many different crosses already, must be around 40 unique crosses harvested already.

I’m now trying to create a system which makes keeping the water levels easier. But still keeping it all passive. I don’t like noise so I don’t want any kind of electrical circulation.

1 Like
29

I’m hoping to cross my wild pimps with the only tomato to make it through my heirloom variety trials (Principe Borghese) which is determinate, with dense fruit, and almost as much vigor as wil pimps (without the tendency to sprawl over 4 square meters).

The only line I am growing with possible species genetics is a mix with some amount of chilensis in it. I can’t remember who I got it from, but I’m pretty sure they were doing some wild tomato breeding and the name stuck (I call is Chile Bronze). It is an indeterminate with enormous vigour, and large slicing type fruit in a smoky chocolate brown colour. Tastes wonderful unlike every other brown/black variety I ever grew. Pests which destroy normal heirlooms leave it alone, even with the fruit dragging in the dirt.

30

To me it seems likely that there aren’t pure pure species within those species that cross easily. Looking at one trait doesn’t tell anything. A population can have off type trait that was passed on 1000 generations ago and natural selection has kept it while otherwise population is 99.9% pure. Or that trait might be eliminated within few generations, but something other lives on that can’t be seen outside. North american wolfs are good example of this. Most populations have varied fur colouration that came from dogs. There are some populations that don’t have it, but it’s likely that over time dog genes have spread trough and natural selection has eliminated some visible colour differences because of enviroment. Some populations might be so isolated (like in islands) that they have stayed pure. That doesn’t apply to plants that make edible berry like tomato.

31

I’m not sure who is looking at only “one trait”. Here are some extracts from the paper ‘Genetic Diversity and Population Structure of Two Tomato Species from the Galapagos Islands’ - Yveline Pailles et al - 2017:

Screenshot 2023-07-17 at 08.18.33
Screenshot 2023-07-17 at 08.18.331774×1492 138 KB

S. cheesmaniae and S. galapagense Can Be Clearly Differentiated by Genetic Analysis

To dissect the pattern of genetic variation among the accessions, we used both PCA from EIGENSOFT 6.0 (Price et al., 2006) and Bayesian clustering from STRUCTURE software (Pritchard et al., 2000). For PCA, the SNP data was further pruned based on LD, to obtain a subset of SNPs that are in approximate linkage equilibrium with each other. PLINK (Purcell et al., 2007) was used to calculate LD, based on pairwise genotypic correlation with a threshold of r 2 = 0.8. LD-based pruning reduced the SNP marker collection to 2,428 SNPs.

The PCA showed a clear division between the accessions identified as S. galapagense and S. cheesmaniae, as well as from S. lycopersicum and S. pimpinellifolium (Figure 3A).
The accessions belonging to S. galapagense cluster closely together (orange diamonds), while S. cheesmaniae accessions are also clustered (green circles), with the exception of two accessions: LA0531 and LA3124 (marked by an arrow), which could be admixtures. Individual PCAs of the accessions belonging to each of S. galapagense and S. cheesmaniae can be found in the Supplementary Materials (Supplementary Figure S2).

The groups obtained from the PCA were identical with those formed by an alternative clustering program, STRUCTURE (Pritchard et al., 2000), which uses a Bayesian clustering approach to identify the number of populations (K) with the highest structure (Supplementary Figure S3). This is determined by plotting Delta K, based on the method of Evanno et al. (2005); our DeltaK plot showed a peak at K = 3 (Supplementary Figure S4), suggesting the presence of three genetically distinct groups that differentiate the two Galapagos tomato species and the tomatoes native to mainland South America (Figure 3B). Once more, accessions LA0531 and LA3124 appear to be genetic admixtures. The admix nature of these two accessions was confirmed by the ancestry membership coefficients (Q), which show that LA0531 belongs to both cluster 1, formed by the rest of S. cheesmaniae accessions (Q = 0.674), and to cluster 2, formed by all S. galapagense accessions (Q = 0.325), whereas, LA3124 appears to be part of cluster 1 (Q = 0.432) and cluster 3, formed by S. lycopersicum and S. pimpinellifolium (Q = 0.568) (Supplementary Table S3). The collection notes of these two accessions, obtained from TGRC database 1 (Supplementary Table S4), report morphological differences from the typical S. cheesmaniae since the time of their collection (Supplementary Figure S1), which confirm that they are hybrids and crossing did not occur during later seed propagation, but in the natural environment. It is also worth noting, that the two accessions are unique to Baltra and Santa Fe, respectively, two very small islands – only one accession was collected from each island (Supplementary Table S1).

The results from PCA and STRUCTURE are largely consistent. For both analyses we found that S. galapagense, S. cheesmaniae, S. lycopersicum, and S. pimpinellifolium accessions are clearly separated. Although the sampling size of S. lycopersicum and S. pimpinellifolium accessions is small, the three reference sequences clustered together in all of the analyses performed. Thus, they provide useful reference points to facilitate estimation of the genetic distance between the Galapagos tomato populations.

A bit further into the paper:

Clustering of S. cheesmaniae Accessions Could Be Similar to the Age of Island Formation

In the genetic distance tree, the S. cheesmaniae accessions separate into two sub-clusters with a 100% bootstrap support, while the admixtures remained separated from the main S. cheesmaniae branches (Figure 4A). Likewise, the population structure inferences using STRUCTURE (Figure 4B) of S. cheesmaniae accessions show two sub-clusters (K = 2) and no further structure within the S. galapagense group (K = 1) (Supplementary Figure S5). S. galapagense showed no structure, even when using the No admixture model in STRUCTURE (Pritchard et al., 2000; data not shown).

Interestingly, the division of the S. cheesmaniae cluster shows clear geographic structure. The grouping of the accessions matches their region of origin: the accessions collected in the western islands separate clearly from those collected in the eastern islands. This can be linked to the island formation timeline, as all the islands originated at the volcanic hotspot and then moved east with the Nazca plate which holds the Galapagos archipelago (Geist et al., 2014). The eastern islands are therefore older than the western islands (Geist et al., 2014) and from this we can infer that those populations found in the eastern islands may be older than the ones found in the western islands; alternatively, they could be ancestors of the accessions in the west. This inference is supported by the comparison of Wright’s fixation index (F ST ) values (Wright, 1951) for each S. cheesmaniae cluster, obtained from the STRUCTURE analysis (Pritchard et al., 2000). The mean F ST -value of the accessions from the western islands (0.6239), is considerably higher than the mean F ST -value of the accessions from the eastern islands (0.2790), which suggests the occurrence of a strong episode of genetic drift on those populations from the newer islands (Falush et al., 2003).

Analysis of Genetic Variation in Galapagos Tomatoes

An AMOVA (Excoffier et al., 1992) was performed to examine patterns of genetic variation and to estimate variance components at the levels of species and accessions. AMOVA showed that 43.1% of the total variation in the Galapagos tomato populations was explained by differences between the two species; whereas 51% was explained by differences between accessions within the species (Table 1). This confirms that the two species are considerably different, but also there is great variation among the accessions within a species.

Best to read the paper for full details but here’s another graphic from a bit further on:

Screenshot 2023-07-17 at 08.26.18
Screenshot 2023-07-17 at 08.26.181450×1792 222 KB

I like this paper because speculation can be useful and interesting, but I do love a good evidence-based approach also. It would seem that from a scientific perspective, these two Galapagos species are clearly differentiated, and, clearly differentiated also from lycopersicum and pimpinellifolium.

1 Like
32

You did when you referred them as pure based on seed size. You can’t make assumtion of pureness based on seed size or any one trait. Pure looking seeds might just as well be from crosses. Unless you collect them yourself there might have been cross and segregation to “pure seeds” before you get them. And not “pure looking seeds” might be more genetically pure. Unless you specifically want to have tiny seeds on your breeding, then you will be getting similar genetic make up. Since accessions are so different you will always have genes that are in some but not in others and so even crosses will have unique to species genetic make-up that is not in some genetically more pure accesions. So looking for complete pureness might be quite futile if you are atleast getting what could be considered within limits of the species.

33

If you’re sure about that, please quote where, but I think you’ll find I never made any such statement. I mentioned the small size of pure pimp. seeds but never claimed my calling them pure was based on their seed size. However I have judged claimed pure accessions to be impure, based on large seed size, such as some of the Galapagos varieties sold by HR Seeds.

Since the only such assumption I made in that regard is the one I just explained, judging large seeded claimed pure wild species to be impure, I welcome you to challenge that assumption if you really do find it to be false. I can give you another example also - I would suggest that based on the single trait of having red colour, you could discount any tomato having that trait from being pure if it is claimed to be from any species aside from lyc. or pimp.

Talking from my own side, if I want to use cheesmaniae for example, then I would much rather get a genuine accession of cheesmaniae, than a falsely claimed pure cheesmaniae that may be 25~50 mixed with some random lyc. or pimp. If I want to mix it with lyc., then I want to chose what lyc. to mix it with. If it’s a 50/50 mix already then that wastes a lot of my time and effort, since I have far less from that species than I could have if I got a genuine cheesmaniae, plus all the junk from the random lyc. that is highly likely to lack the characteristics I want in a lyc. and have characteristics I specifically want to be rid of. For example, suppose I could end up making a great tomato that has, just for argument’s sake let’s say 50% che. if I were to use pure che., and lycs of my choosing (which are most likely to have some hab. and maybe pen. or others in it too). If I start instead with a random 50/50, then I need to add more lyc., let’s say to 75/25, but still my own lyc. qualities are fighting against the junk lyc. Not a desirable situation for me.

Same goes for pimp. If I want to mix pimp and Galapagos species, then I will chose what pimp based on my needs, rather than go for some random mix out there.

This is why for me personally it is actually quite important to not mess around with fake ‘pure’ accessions, and instead do the work with genuine accessions.

Having said that, I have made some crosses with such a fake accession, but only because I acquired it before the genuine accessions, so I figured I may as well cross with it since I have it growing here. But those crosses will be a much lesser priority for me.

Indeed. Hence I am using multiple pure gal. and che. accessions to cross with. Along with multiple accessions of other wild species I’m working with.

34

Ah, yes, good point. Also the landrace ‘Columbianum’ I have is a cherry tomato. I would be interested to know the size trends in the landraces in general, like, I wonder what the biggest size they get to is, among those that haven’t been mixed with tomatoes that left South America. I’m guessing the main size increase was done after the bottlenecks occurring after leaving that continent…

Also some seem to speculate that some of the ‘cerasiforme’ might have been usual domestic tomatoes that went feral and then reverted to some degree in their traits.

In case it is of interest, here’s a couple of extracts from TAXONOMY OF WILD TOMATOES AND THEIR RELATIVES (SOLANUM SECT. LYCOPERSICOIDES, SECT. JUGLANDIFOLIA, SECT. LYCOPERSICON; SOLANACEAE) Iris E. Peralta - 2008 on cerasiforme:

We do not recognize taxa below the species level, most notably the small-fruited tomatoes known to many as “var. cerasiforme.” The name “cerasiforme” has been used to refer to putatively wild forms of S. lycopersicum that have been regarded as progenitors of the cultivated tomato (although see Frary et al., 2000, and Nesbitt & Tanksley, 2002). It is impossible to distinguish wild from cultivated forms using herbarium specimens, and we regard many specimens labeled as “var. cerasiforme” to be possible revertants from cultivation (i.e., feral plants) or possible hybrids of wild and weedy taxa.

DOMESTICATION OF THE CULTIVATED TOMATO

Two competing hypotheses have been advanced for the original place of domestication of the cultivated tomato, one suggesting an origin in Peru, and another an origin in Mexico. Candolle (1886) advanced the Peruvian domestication hypothesis based on botanical (Bauhin 1623; Ruiz & Pavón 1797), linguistic (Roxburgh 1832), and historical (Hernández 1651) evidence and concluded: 1) there were no unambiguous natural records of tomato outside of the Americas before the arrival of European explorers, 2) Bauhin (1623) referred to tomato as “mala peruviana” and “pomi del Peru,” which suggested initial domestication and transport of tomato from Peru to Europe, 3) its origin was from the wild cherry tomato (S. lycopersicum, “var. cerasiforme” of prior authors), which by Candolle’s time was known from coastal Peru, and in Mexico and the southwestern U.S.A. (California), 4) the distribution of cultivated tomato and its progenitor outside of Peru originated by garden escapes, and 5) the plant was domesticated only just before the discovery of the Americas by Europeans. Candolle’s hypothesis of Peruvian origin was later supported by other authors (Moore 1935; Müller 1940a, b; Luckwill 1943a, b), but recent genetic investigations have shown that the plants known as “cerasiforme” are an admixture of wild and cultivated tomatoes rather than “ancestral” to the cultivars (Nesbitt & Tanksley 2002).

35

That still leads to assumtion that you can increase pureness by looking at the seed size. Both can be just as impure or pure, and small seeds can be less pure. Where do you get that 50/50 mix? Just because some accessions are mixed doesn’t mean they are by that much. Might be more like 98% pure in any case whether it’s small or big seeds. Or it might be 90% for small seeds and 99% for big seeds. If seed seller gets them mixed up again that is another story again. If it’s accession classed as cheesmaniae then it should not be 50/50 mix. Granted seed sellers don’t always care, but that doesn’t make seed size either way any better indication of pureness. Bytheway, how do you know yours are pure?

36

In my mind, it does not lead to that assumption. And if that assumption you have made from it is false, I do not think you should blame my statement as the cause of such a false assumption, if my statement was correct.

Both what? You believe that a claimed pure wild species can be 100% pure wild species and yet consistently have seeds the size of domestic lyc.? If so, I welcome you to provide some evidence. If you can prove that to be the case then I would gladly change my view.

Please note I wrote:

I also mentioned “falsely claimed pure cheesmaniae that may be 25~50 mixed”.

If you have a che. that is 98% pure and you want to use it, you are most welcome to do so! If I see a random seller selling non-genebank seeds for a plant that has clearly mixed heritage evident from seed size and is phenotypically very clearly not pure cheesmaniae in terms of leaves and fruit, then I’m not going to assume it’s 98% pure. In my opinion it is far more likely to be a recent hybrid, and in my opinion highly likely to have been crossed just once (hence 50/50) or perhaps twice being backcrossed if one’s lucky enough (hence me saying “may be 25~50 mixed”). And indeed this is an ongoing issue not just for people selling commercially in the West, but also on the Galapagos islands themselves. If interested in the threat of the native Galapagos tomato species posed by invasive species, there is discussion of that in the paper ‘The systematics and genetics of tomatoes on the Galápagos Islands (Solanum, Solanaceae)’ - Sarah Catherine Darwin - 2009

Yes, it should not be. That doesn’t mean it isn’t. It just happens to be a fact that some sellers don’t know what they’re selling, and, some sellers flat out lie. I think even Joseph [edit: correction, it was Andrew Barney] mentioned a cheesmaniae hybrid which he really liked, and knew to be a hybrid, but the seller refused to publish his review of it despite it being a very positive review, seemingly because he pointed out that it’s actually a hybrid. Money is sometimes a stronger motivation than the love of truth.

You say ‘better’ but I don’t see you saying better than what. I also don’t see you giving any basis for claiming what I have said is wrong, so I am not really sure what the point of this is.

Extensive genetic analysis. Did you read the materials I provided for you?

I am struggling to see how this is going in a useful direction right now.

37

I believe that was Andrew Barney. Not Joseph. Andrew did some extensive research on some of these wild tomato species and wrote a very interesting blog post a few years back.

Andrew sent me most of the accessions of Solanum cheesemaniae and Solanum galapagense that I grow. Those he considered to be true wild accessions he obtained from a gene bank in California. The one from a seed seller was much larger and had larger seeds.

As Justin noted some of the crossing may have occurred on the Galapagos islands themselves.

I believe Andrew’s earlier research and Justin’s more recent research is accurate. Accessions with smaller seeds are likely more authentic though segregation can occur in hybrids. This should not be a point of contention.

In my view I tend to think the sellers are not malicious, nor do I think they make much money on these tomatoes. I don’t think tomato seed selling is particularly profitable. I rather think they simply haven’t taken the deep dive into it that Andrew and Justin have. It is a fine point and many folks simply don’t have the tenacity. Also, some of the tomatoes that may be hybrids are of a very nice variety.

Personally, I have found all these Galapagos Island tomatoes a bit difficult to make crosses with. The problems seem to be entirely mechanical. They have small flowers with very slender styles. I’ve grown them repeatedly and attempted crosses. Bees don’t seem to cross them regularly with larger flowered tomatoes. I think the bumblebees tend to separate the species and work one at a time though I haven’t quantified that observation. I need to make more crossing attempts this year. I thought I had one take, but then lost it.

I’m having the most success making crosses of crosses with a Solanum galapagense cross I found amongst my seedlings last year and now the cross I made with it.

38

Ah sorry, thanks for the correction. I think it was the photos being from Joseph that threw me off.

I might be somewhat more skeptical. I wrote to HR Seeds citing evidence for 2 of his identifications being wrong - no answer. Similarly with Andrew, if that site routinely published customer reviews but specifically refused to publish his 5 star review, that makes me think there is some less than noble motive at play. To quote from his article you shared:

A company that sells one of these hybrid tomatoes, but refuses to post my honest 5 star review is Terrior Seeds / Underwood Gardens. They have a lovely Galapagos Island tomato hybrid that was indeed collected from there , but is actually a hybrid. They refuse to believe me or publish my review despite it being one of my favorite tomatoes to grow and eat.

In contrast, I wrote to a genebank citing my own observations and evidence for their misidentification, and they promptly corrected their website data. That to me shows a difference of motivation. I would not necessarily label that as ‘malicious’, but I would assume a fair possibility of some less than noble intent there. I would however not necessarily assume the same for sellers unwittingly selling hybrids who have not been presented evidence to inform them, and have simply assumed the info they were given by their source, was correct.

Yes indeed, and this is of course also worth bearing in mind. Though I think we are better off knowing what we are dealing with, where possible.

I wish you better luck this year! I have numerous fruits ripening now from cross attempts in both directions, so I am hoping they will bear crossed seeds. One thing I have been doing outside is putting a small bag over crosses for the first day or two, hoping this will increase the chances, in particular by stopping the pollen from blowing away. I use the same small bags I use for seeds, and I cut the bottom open to prevent too much build up of humidity. This also protects them from rain, which I would assume might explode the pollen - we get unpredictable showers here!

Also when crossing to galapagense as female, for most of them I have not removed the entire anther cone, just the front bit, basically making an artificially highly exserted stigma. Doing this in the hope that

  1. my chosen pollen will fertilise it before its own pollen gets the chance to be produced,
  2. its own pollen will anyway have little chance of reaching the stigma (not only due to the new exsertion but also because of having removed the flowers, thus discouraging pollinators from vibrating the flower)
  3. the style will not dry out too much, being only partially exposed.

Yet to see how this will turn out in final results but I can at least say that several of them are now bearing fruit, so perhaps point 3) has worked. And I even do this with some crosses I’ve tried to make to exserted accessions of pimp. and gal., exaggerating the exsertion to increase chances, and since pimp cross attempts have in some cases given endosperm-less embryos (cross attempts with per. and arc.), it would seem this has been working, indoors at least. Fingers crossed for the outdoor gal. crosses!

I have also found that I can get far more pollen using a tuning fork than with my vibrator. Although this might have more to do with the fact that the rechargeable battery I installed in this tiny vibrator bought for this task, was last charged many years ago!

1 Like
39

Jesse here’s a quote for you from Andrew’s article that William linked to:

One word of caution though if you decide to go looking for seeds for these Galapagos Island tomatoes. You almost certainly wont find pure S. cheesmaniae or pure S. galapagense seeds out there except direct from a seedbank. There are a LOT of snake oil salesmen out there that claim to have them, but while it is possible that they have some wild galapagos tomato heritage, these varieties are almost certainly not pure. Some may very well have S. cheesmaniae ancestry, but are not pure. I have yet to grow out many accessions of S. cheesmaniae and access the genetic diversity in the species, but one that set fruit this last season was about the size of about the nail of my ring finger. Super tiny. One way you can tell if they might be authentic is if the seeds themselves are incredibly small. But if they are the same size as regular tomato seeds they are not pure.

40

What I’m trying to say there isn’t such thing as pure. It’s just a human invention. Even your studies clearly point out the genetic diversity. What is considered pure species includes also some genes that have been passed from crosses over time. Most notably homo sapiens is an interspecies cross and we are still “pure” species. If crossing can happen it has happend a lot. It might not leave more than trace amounts even within very short time, but it can leave traits that make it stand out. Or it might leave something that doesn’t stand out. Or every trace might be eliminated whitin short period of time. I was only referring to wilds that have been classed as one species. I don’t think we are qualified to make judgement on professionals who have classified them. If some shady seller uses scientific name wrongly or has them crossed out of wild by mismanagement doesn’t mean that all accesions that have had seed size increased by earlier cross are somehow junk. If you have some studies that make clear difference between seed size to pureness you are free to share. I just don’t nature works like that. it’s a lot more chaotic than anyone can even comprehend.

2 Likes