Promiscuously Pollinated Tomatoes And The Bees That Make Them Possible

Even though this post seems to be about tomatoes, in my mind, it is primarily about the species that pollinate tomatoes, so I'm sticking it in the bees forum. I intend follow up posts to have a lot to do with bees.



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I am working on a project to convert the tomatoes in my garden from a population that is primarily self-pollinating, to a population that is primarily cross-pollinating. That means that the flowers need to be more attractive to pollinators. In my garden that is probably bees. It seems to me that if two heirloom tomato varieties are crossed to make hybrid tomatoes, that the hybrid offspring (averaged over many crossing combinations) produce about 50% more fruit than the most productive parent. I think that explains why hybrid tomatoes are overwhelmingly preferred over heirlooms by people to whom productivity is very important. More natural cross pollination would mean that I am growing more naturally occurring hybrids and could thus expect higher productivity.

I live in a climate that is near to the ecological limits of tomatoes... That means that about 90% of the varieties I trial fail to produce ripe fruit in the available growing season. If I grow heirlooms, or commercial hybrids, I am growing varieties that were selected for different conditions in far away places with different soils, and sunlight, and weather, and bugs, and microbes, and farmer's habits. Heirlooms have been inbred for as many as 50 or 60 generations. They tend to do poorly in my garden. I attribute their poor performance to a combination of inbreeding depression, and not being localized to my growing conditions. Commercial hybrids are expensive because I would have to purchase the seed every year. I could make my own hybrids, using varieties as parents that are known to thrive on my farm. That'd require meticulous care to make sure I maintain the parent lines, and that I make the crosses correctly, and keep the paperwork straight. Not really my way of doing things. I prefer as much as possible to allow the natural systems around me to take care of cross pollination.

A few years ago, I was doing a trail for frost/cold tolerance in tomatoes... I noticed two varieties in the trail that had bumblebees on them pretty much any time I walked past the plants. The bees visited other tomato plants on scouting expeditions, but didn't hang around for long periods of time collecting pollen. Those two plants also happened to be the most productive plants in my garden that growing season. (One of them has become my main early season production tomato.) The plants were highly attractive to bumblebees because they drop clouds of pollen when shaken.

That got me to thinking about how glorious it would be if I could return my tomatoes to closer to their ancestral state of being mandatory out-crossers. That would allow lots of new genetic combinations to be generated without requiring manual pollination. And with the genetic roulette wheel spinning faster, I can expect local adaptation to occur much quicker. So I started paying attention to the flowers on my tomatoes to see if I was currently growing anything that might be more susceptible to cross pollination.

The tomato that drops clouds of pollen has flowers that look like this. I call this an industrialized type flower. It's all closed up to prevent cross pollination. Makes the purists happy. At least it drops clouds of pollen, so it's not as industrialized as it could be.

Industrialized flower.


The nearest thing to an heirloom tomato for my valley was developed for the Campbell's soup company about 45 years ago. It grows great here, although technically, it was developed for the next valley to the west which is at lower elevation and thus has a longer growing season. So it requires just a bit longer growing season than my garden provides. But look at those wide open flowers! Pollen can get all over that stigma. The anther cone is open. Pollen can easily get in and out of the flower.

Open flower.


So I made a manual cross pollination between these two varieties...
I am hoping to find offspring among the grandchildren that combine the trait of open flower structure with the trait of dropping clouds of pollen and being highly attractive to bumblebees (or other pollinators). I grew the F1 hybrid in the basement overwinter, and currently have second generation plants growing in the greenhouse. They are ready to be planted into the field soon. It would also be nice to combine the super early productivity of one of the parents with the larger fruit size of the other... Here's what they looked like a few minutes ago.

F2 Hybrid Tomatoes: DX52-12 X Ot'Jagodka



I also found other varieties with loose or open flower structures and tried to make crosses. Here's what one of the flowers from one of those varieties looked like. I mostly flubbed the cross pollinations. (I should have put pollen from the long season varieties onto a short season tomato. I did the cross the opposite direction, so most of the fruits didn't mature before getting frozen.) But I was able to grow a few of these during the winter and have some F2 plants currently growing. One of the plants where the cross succeeded was to Hillbilly which is an orange/red tomato. I'm excited about that because I prefer the taste of orange or yellow tomatoes. Eventually I may convert all of my tomatoes to orange.

Beelover's Tomato: Croatian Brandywine


So this year, I'm expecting to be looking at lots of tomato flowers to find flowers that are wide open to pollination, and that the bees adore. I'm not fixated on using bumblebees, I'd select for flowers that are attractive to any species of pollinator. Bumblebees were the pioneer species that got this project started, so they are likely to play a big role in selection.

Longer term, I am looking for genetics that can be incorporated from wild tomatoes to require crossing by using self-incompatibility genes.

Eventually, I want to get the promiscuous pollination trait sufficiently established so that I can send the tomatoes into areas for trial that are really bothered by dampness diseases such as late blight... Instead of throwing a few hundreds of heirlooms and commercial hybrids at the problem, we can throw tens of thousands of plants at the problem which are able to easily swap pollen with each other and self-select for the perfect combination of genes to handle changes in the environment and in the microbiome. If I find a particular species of hole nesting bee that really takes to the tomatoes, then it might be possible to share the bee at the same time as I share the tomatoes.

Further Reading:
Landrace Gardening: Promiscuously Pollinated Tomatoes

Here's a photo that demonstrates the dramatic difference in flower type between a tomatillo which requires cross pollination, and a tomato that is self pollinating. The tomatillo flower, on the left, has huge petals. Both the male and female parts of the flower are wide open and fully exposed to pollinators. Additionally, some of the leaves on the tomatillo plant turn yellow, exactly matching the color of the flower petals. I suppose it's another tactic that the plant uses to draw pollinators to the flowers. And what about the dark stains on the petals? Another accommodation to pollinators? The tomato flower is closed up and inconspicuous. Doesn't seem like there is much there to attract a pollinator. At the farmer's market if I take tomatillo plants that are in flower, there is no end to the comments about the floral display. I rarely get a comment about flowers on the tomatoes. Hmm. I'll work on changing that by selecting for tomato flowers that are more like the tomatillos.

Hey Joseph, fascinating work! Can't wait to see photos of the different types of flowers you get in the F2 generation.

Have you talked with Tom Wagner about this project?

Sam: I found these flowers yesterday. They are descended from Sungold. We speculate that Sungold has a wild ancestor (Solanum habrochaites) with large flowers and extra long styles. This plant called attention to itself by having extra large flower petals. When I looked closer I was thrilled that the stigma is outside the anther cone which aught to really increase the rate of cross pollination. I grew out about a hundred of these this spring, but only kept 6 plants for myself. Some of them have more industrialized-type flowers. Boo Hoo. If I had known, I wouldn't have been sharing....

Yesterday I planted some Solanum habrochaites seeds, and some seeds of a cross between it and a wild cherry tomato. I expect that I'll need to ripen them in the greenhouse this fall, so I'm putting them into pots.

I haven't talked with Tom about this project.

Tomato flower with exerted stigma and extra large petals.


Today I installed a bee nesting log into the tomato patch.


I put many different sized holes:


In the barn I installed a more formal block with like sized holes grouped together. Perhaps making it easier to match up species visiting the tomatoes with what's using the nesting block. I read that more bees are ground nesting than wood nesting, but gotta start somewhere.

Micro-bees were visiting the tomatillos today, but I wasn't able to capture a good image.

Today I spent a couple hours in the tomato patch looking at the flowers under high powered magnification. A few were really exciting to me.

This one (of unknown heritage) has super large flower petals and an exposed stigma: Just the sort of thing I am looking for in my quest to get flowers that are more attractive to bees. The flower size is approaching the size of tomatillo flowers.


This one has a stigma that pokes way outside of the flower: Just the sort of thing to rub up against the belly of a bee and swap pollen with a friend. This plant is the F2 of a cross between DX52-12 and Jagodka:


I tried to cross pollinate a couple of flowers, but they are just starting to flower, and I was ham-fisted so I broke the flower... Boo hoo. Better luck next time.

I spent about an hour in the tomato patch today examining the plants from one of the F2 clades for the promiscuous pollination project: [Hillbilly X Jagodka]. There were two plants with exerted stigmas, (that can easily rub up against the bellies of bumblebees). One of those two was a determinate... Woo Hoo! That's two of the traits I am looking for in the same plant. There was another plant with promiscuous-type flowers, but it was an indeterminate: Not the best fit for my climate. And there was one other determinate plant, but it has industrial-type flowers.

A small bumblebee was visiting the flowers while I watched.

Another clade I made to attempt to get promiscuous flowers didn't produce loose/open flowers: [DX52-12 X Jagodka]. However, the grandparents are two of my favorite tomatoes, and some of the offspring aught to work really well in my garden even if the flowers aren't all that I had hoped for. Perhaps the flower type I'm after will show up in the great-grandchildren. Early on this clade produced a couple of flowers with exerted stigmas, but the plants reverted to industrialized-type flowers, so I'm attributing the unusual flowers to the extreme heat we had as they were opening.

I've been finding some promiscuous looking flowers among F3/F4 plants that are descended from SunGold. The bumblebees really like these.

? about tomatillo pollination. I have been buying on tomatillo plant each year. Do I need more than one plant to get fruit?
I put the plant with a cantaloupe so that the trellis could hold it up this year. Micro bees were pollinating the very small blossoms on this variety of cantaloupe and they were also visiting the Tomatillo flowers. I found one tomatillo fruit had fallen when I was weeding at the end of August. No sign of any other fruit forming. I had them in my high tunnel which I closed up mid September then while I was away from home the temperature sorred into the mid 80's and scorched the leaves on the two plants. the high/low thermometer in my tomato house reached 120, Interestingly the flowers are still there on the bare stems still looking pretty.

Tomatillos are self-incompatible, which means that at least two plants are required for pollination. I finally got smart this spring, and included two tomatillo plants in each pot at the farmer's market. If I grow them next year I'll include 3 plants per pot. Then the odds would be really good of getting compatible genetics. They'd grow fine as a clump.

Joseph Lofthouse wrote:I spent about an hour in the tomato patch today examining the plants from one of the F2 clades for the promiscuous pollination project: [Hillbilly X Jagodka]. There were two plants with exerted stigmas, (that can easily rub up against the bellies of bumblebees). One of those two was a determinate...

Here's what one of those plants looked like. I am calling it HX-9. It is everything that I hoped for from this cross: Determinate. Early. Very productive. Open flower structure. Large bicolored Red/Yellow fruits. I am intending to plant a lot of them next year... The traits for determinate vine, open flowers, and yellow fruits are all recessive traits, so they should be fixed in the descendents. The traits of earliness and large fruits may be less stable, since they depend on many genes, but I expect the offspring to be very similar to their parent. I expect to have seed to share in a few weeks.



Another plant from this clade that I really liked was HX-3, which was also determinate and had bicolored fruits, and was early, but it had closed flowers.



And I kept a tomato, HX-13, with basically none of the traits that I am looking for, because it produced lots of early fruits!


I also kept seeds from a couple of other plants: one that had exerted stigma, and one that had an interesting foliage pattern.

I saved seeds from about 20% of the [DX52-12 X Jagodka] F2 plants. I'm calling them DXX-M I didn't find any open flowers among them. Maybe next year.


Some of the descendants of Sungold looked interesting. And the bumblebees liked visiting them.

Love your experiment, and hope you succeed at it.

One of the oldest tomato varieties we have is the yellow pear - and it has an exerted stigma, which makes it more amenable to cross pollination.

One correction - there are no tomatoes that are self pollinating, despite the mythology. What you refer to are tomatoes that are self fertile, or self pollenizing. Tomatoes need help to pollinate. Not saying that there is NO self pollination - but the percentage is very, very small. If you don't believe this, try growing tomatoes in a greenhouse where there are no pollinators, and no wind.

Wind - and other forms of motion will distribute some pollen, and can give some fruiting, but to maximize fruiting the flower needs to be buzzed or "sonicated." This releases the greatest amount of pollen, and ensures that all the incipient seeds are fertilized. (you do know, of course, that full pollination - the delivery of two grains of pollen for each incipient seed - gives the best size and quality of fruit.

Bumble bees (B. impatiens and others) buzz the flowers. This releases vast quantities of pollen instantaneously. The bumble bee uses the resonant frequency of the flower (Middle C) in vibrating its wing muscles. You can imitate this pretty well with a tuning fork. If the flower is ready for pollination, pollen will spew out of the flower.

I have not seen any of the solitary (hole or ground dwelling bees) do buzz pollination. Honey bees will occasionally gather pollen, where they pull down the flower and shake it some, so they may accomplish some pollination, but they do not buzz in the same fashion that bumble bees do. And some years, they never go near the tomato blossoms.

Not all of this is directly relevant to your experiment, but is background information that may help you design better experiments.

One of the long-term goals of this project is to modify the phenotype of my tomato flowers so that they are more akin in shape to tomatillo flowers... That includes open/split anther cones, or even totally unconnected anthers, exerted stigmas, and huge fused petals. Another trait that I see in tomatoes, but not tomatillos is for flowers to be born high above the foliage. I see lots of small flying things fussing around with tomatillo flowers. I aim to convert the tomato flowers into something that small flying things will mess around with. And while messing, perhaps they will transfer some pollen. A trait I observe in tomatillos that I haven't in tomatoes, is for the leaves to turn the same color as the flower petal. People would whine that their tomatoes are looking sick. But it might be worth it to attract more small flying things to mess around with the flowers.

This year, I am making manual crosses to start the process of combining the various traits into a single family. I think that there are perhaps 6 flower traits that I want to eventually incorporate into the same plant. For this year, I am making crosses to combine various pairings. Then in a year or two, after a particular pairing is stable, I can add in other desired traits.

Can you imagine? If the seed saving instructions for a variety of tomatoes was, "Save seeds from at least 100 plants."

The particular variety of "Yellow Pear" that I'm growing has been industrialized, so the stigma is not exerted. Several of the crosses on my to-do list include crosses with yellow pear as a parent. Since I am highly focused on growing determinate varieties, a determinate yellow pear will likely be one of the by-products of these crosses.

I have made a lot of crosses using this plant as a pollen donor. The stigma is highly exerted. Just the thing to rub against the belly of a bee.


Fruit is ripening today of a cross between the previous plant, and this one. Again the stigma is exerted. However, the flower is tiny and unobtrusive. Need to work on floral display!


I'd like to get a cross made between this plant, and something with an exerted stigma. The flowers are very showy! Just the thing to attract fliers.


I've used this plant as a pollen donor to a number of crosses. The flower is huge. The anther cone is open/split. And the stigma is exposed. I'd like to get the stigma more exerted.


This flower is from a wild tomato species, and it has the petal structure of a tomatillo. Alas, it's not directly cross compatible with domestic tomato, but I'm attempting crosses to work around that... It also has an exerted stigma to rub against a flier.


Tomatillo vs tomato flower.


Too bad that Brandywines do so poorly here. That's a gorgeous flower!


This variety contributed to a few of my crosses for this project. So far, I have been able to identify the open flower trait in three of the F3 generation [DX52-12 X Jagodka]. I've set them aside for making crosses.


I just finished planting about 300 tomato plants, into the field, for this project. I have more than that in the greenhouse still that I'm intending to screen for open flower structures.

It will be sad to throw away all of my old favorite varieties to make room for the promiscuously pollinating tomatoes, but today, I settled on three of my favorites that I'm intending to grow as legacy varieties. I planted them in isolation... I may not grow any of the rest next year.

One of my tomato plants reminded me of this thread. I was walking past and a pair of overly aggressive wasps got angry at me. Being of a contrary nature, I told them to buzz off and went to investigate what had them so excited.

Most of my tomatoes look like this:



However, this plant looks like this:







(three different flowers)

It's also the first plant to open its blossoms, starting about 3 days earlier than the next one. I don't know what kind it is, as I deliberately didn't label this year.

I don't know how well it shows in the photo, but basically, it has its sex bits hanging out. Talk about promiscuous. The cone(?) which normally guards the seed making equipment, is splitting open like petals, and I can get pollen by lightly brushing my hand against the flower.

Just thought you'ld like to know that your project has me thinking about tomato flowers in a whole new way.

R Ranson: What glorious tomato flowers!

Lol you are infecting our minds Joseph. I selected my tomato starts this year (always buy a few, squirrels hate my seed trays) by the most promiscuous flowers. I grabbed two different kinds with the same type Ranson posted. Don't know the names, I too deliberately did not label them.

Here's a few photos of a bee that was working the tomato flowers today. There were two other species flying around and messing with the flowers that I was  not able to capture clearly in photos. Gotta love the bold floral display on this plant!

I spent about 5 minutes watching the tomato flowers today. I observed the following species working the flowers (my own guesses at names): that black/white striped bumblebee digger bee, two species of hover-flies, and two species of micro-bees.

Edited with better guess at species name...

I am not expert enough to say categorically, but I don't think that's a bumble bee on the tomato blossoms. I think it's an Anthophora (digger) bee. It doesn't look quite right for a bumble bee to me, plus the Anthophora bees have a habit of flying with their tongues hanging out. If this is true, you are blessed to have them

With your permission, I'd be glad to send the photo on to a friend of mine with more expertise.

Did the bee buzz the flowers, as a bumble bee would?

Possibly Anthophora urbana   http://bugguide.net/node/view/78939

David: Thanks. Share away. These bees buzz pollinate the flowers, but the frequency that they use is somewhere around 2000 Hertz. I've never heard that kind of sound coming from a bumblebee.

Here's an audio track of the digger bee pollinating tomato flowers. The low pitched sounds are of it flying. The high pitched sounds are of it curled up around the anther cone on the tomato flowers.

Digger Bee Pollinating Tomato Flowers

Here's an audio spectrum analysis of it flying compared to buzz pollinating.

Flying:


Buzz Pollinating:


And finally a spectrum analysis of the whole audio clip. Easy to tell when the bee is flying, and when it's pollinating...

I love your graphs!  My expert friend confirmed my suggestion of Anthophora, but said he couldn't confirm species from a photo. Fair enough, I think.

You've got me checking out my tomato flowers, along with the bees. These are some of the 'promiscuous' flowers I've found. Looking forward to next year to see what I get from this year's seeds.

And thank you, Joseph, for being so free with your knowledge - it's a great help to those of us who are new players in the plant breeding/landrace game. Greatly appreciated!

Tracy: Thanks for photos.

Last evening in the garden I noticed a honeybee working the wild tomato flowers:

Solanum habrochaites


Solanum peruvianum. During the day these flowers are wide open. They close in the evening.  

More from the wacky world of pollination....  https://www.theguardian.com/science/2016/aug/11/cunning-cucumber-virus-alters-plant-aromas-to-attract-bees

I posted this in another thread, but it got moved to the abyss that is the internet. So i guess i will try posting it again here in hopes it stays and is of some value to someone. If it dissapears again, then oh well, it is of no great importance.

You might look for something similar to this to know if a flower has been visited by a pollinator:

Pollinator preference was scored asthe percentage of flowers with pollination marks relative to the total number of open flowers on the respective in florescence. Pollination marks are typical brown spots on the tomato flower anther cones, which appear within 5 min after a pollinator visited (Fig. 1c). They are exclusively a result of small injuries that are caused bythe pollinators when manipulating the flower for pollen harvest and are good indicators for pollinator visitation,pollen deposition, and thus pollination success. The percentage of flowers with pollination marks and the percentage of fruit set was strongly correlated in our surveys (Spearman correlation, r¼0.606, P,0.0001;Appendix B). Moreover, pollination marks can be easily distinguished from injuries caused by other flower visitors, such as thrips.

Herbivory-mediated pollinator limitation: Negative impacts of induced volatiles on plant-pollinator interactions (PDF Download Available). Available from: www.researchgate.net/publication/51662618_Herbivory-mediated_pollinator_limitation_Negative_impacts_of_induced_volatiles_on_plant-pollinator_interactions [accessed Jun 14, 2017].

www.researchgate.net/publication/51662618_Herbivory-mediated_pollinator_limitation_Negative_impacts_of_induced_volatiles_on_plant-pollinator_interactions

FIG. 1. Pollinators and their marks on Solanum peruvianum flowers. (a) Colletes sp. (Colletidae) and (b) Corynura sp.(Halictidae) bees vibratile (‘‘buzz’’)-pollinating flowers. (c) Typical pollination marks on a S. peruvianum anther cone appearing 5min after visitation by a bee. For a sense of scale: (a) typical Colletes individual is 15 mm long; (b) Corynura is 8–10 mm long; and(c) anther cone is 10–12 mm long.

Shoutout to Joseph Lofthouse and the bees that make wild tomato crosses and breeding possible!

This is only one photo of one LARGE type of bumble bee, but i observed three bees in total visit the wild S. pennellii and S. habrochaites, and the F1 Solanum pennelli-domestic tomato hybrids. The medum/small bumble bee early in the season was about the same shade and size and appearance as those that visit sunflowers. A small black halactid type? bee was also pollinating early in the season.

1504462611808 by Andrew Barney, on Flickr

1504462611526 by Andrew Barney, on Flickr

1503516858918 by Andrew Barney, on Flickr

Fascinating info. Now I'm wondering what honey made from tomato pollen tastes like. Did a quick online search & found plenty of recipes for combining honey & tomatos but I'm curious about the honey the bees themselves would make from tomato pollen sources. Has anybody tried producing or even seen such a thing?

To the best of my knowledge, tomato flowers only produce pollen, they do not produce nectar.  That goes a long ways towards explaining why honey bees more or less ignore tomato flowers.

Yes, that does make sense. Yesterday was a long tough day. Thanks.

No photos of bees today, but just had to share this awesome photo i took of a Solanum peruvianum flower this week! Can i just say that i LOVE these flowers! This species of tomato had two different kinds of bumble bees visit it last year a large and a medium, and some small black micro bees. The flowers are such a deep bright yellow they really catch your attention. In comparison, domestic tomatoes and genetically related species such as S. cheesmaniae have small closed pale flowers that are ugly.

Wild tomato patch 2018 by Andrew Barney, on Flickr

Wild tomato patch 2018 by Andrew Barney, on Flickr

@Joseph, i love your wild tomato breeding project. I really really hope S. peruvianum can be incorporated into a domestic-enough-like tomato. These genetics are pure GOLD!!!

Andrew: Thanks. I love the flowers of Solanum peruvianum, and Solanum corneliomulleri, and some accessions of Solanum habrochaites. It's looking like plain old selection could dramatically improve the flavor and agricultural properties of the wild tomato species. Here's some photos of Solanum peruvianum. They are a bumblebee magnet in my garden, and highly attractive to other species.

I like that idea! Sure Why not select for flavor in the hard to cross species?!

How attractive to bees are your WTF and WTO line of hybrids with the good flowers doing?

Andrew Barney wrote:I like that idea! Sure Why not select for flavor in the hard to cross species?!

For example, This is the third year of selection for Solanum corneliomulleri. Some plants have fruits on them that are 10X the weight of the fruits on my original plants. Most plants this year have more fruits on even a single branch than the combined harvest of dozens of plants in the previous two years.

Andrew Barney wrote:How attractive to bees are your WTF and WXO line of hybrids with the good flowers doing?

The plants from those breeding lines this year seem to be self-incompatible, and have tightly closed anther cones with highly  recessed stigmas. So they are not at all attractive to pollinators. In the unlikely event that they produce any fruits, that actually have some seeds, they will be a low-priority population to me.

Other lines are highly attractive to pollinators, and have open flowers and exerted stigmas, and seem to be self-incompatible, therefore focus will shift to other lines.  

Joseph, I sent you back a sample of the possible Solanum cornelio muelleri x S. Peruvianum from 2017. Did you grow it out and if so do you still think it's a hybrid? I just seed saved a plant of it, a child of one that survived two frosts last year, that I think is pretty early compared to the original.

Also with the increasing fruit size you mentioned- any chance that their could be hybrids lurking in these populations?

It really seems to me that what I am now referring to as my Peruvianum complex is adapting to my garden rapidly and is able to self seed. I even had one plant move across the garden.

William: I stare a lot at the Solanum corneliomulleri plants to try to answer that question... Half of the corneliomulleri plants this year are descended from the seed that you returned to me. They are the population that has the plant with 10X larger fruits, and plants with huge abundance of fruits. And a plant with wholly purple fruits. And they are early! None of those traits have been noticeable in the S corneliomulleri population in the past. So it seems like they might be hybridized. It's really hard in a species -- that is so genetically diverse to start with -- to identify hybrids based on things like leaf/flower shape.  But then, this is the third successful generation in my garden, and I call that the magical year in my plant breeding efforts, so I don't know how much of the improved growth to attribute to plain old selection, and how much, if any, to attribute to hybridization. I certainly plant in such a way as to encourage natural cross pollination within and between species and complexes. I'm growing a crossing block containing 7 species and 2 families of interspecies hybrids. They aren't necessarily compatible with each other, but I'm certainly inviting genetic exchange between them.

I'm intending to pick the corneliomulleri fruits plant by plant, to see if any differences jump out that wouldn't be obvious in a bulk picking.

This year, I planted patches of S peruvianum, S corneliomulleri right next to each other. I'm really toying with the idea of listing them as Peruvianum complex in my next seed catalog.  A patch of S habrochaites was planted a few feet away. Also nearby were patches of [domestic X habrochaites] and [domestic X pennellii], so perhaps there might be a little back crossing going on as well. At least I'll be watching for it in future years.

I'm wishing that I'd have planted the bulk of the S habrochaites plants closer to the [domestic X habrochaites] plants. That might have encouraged more back crossing to S habrochaites. The rows are only about 24 feet away, but still....

I have a population of S peruvianum that is self-seeding. There are two plants among the volunteers that look like they might be habrochaites/peruvianum hybrids. They may get frozen in a couple weeks unless I dig them and bring them inside. They aren't anywhere near to producing fruits.

Joseph Lofthouse wrote:William: I stare a lot at the Solanum corneliomulleri plants to try to answer that question... Half of the corneliomulleri plants this year are descended from the seed that you returned to me. They are the population that has the plant with 10X larger fruits, and plants with huge abundance of fruits. And a plant with wholly purple fruits. And they are early!

I have a population of S peruvianum that is self-seeding. There are two plants among the volunteers that look like they might be habrochaites/peruvianum hybrids. They may get frozen in a couple weeks unless I dig them and bring them inside. They aren't anywhere near to producing fruits.

Out of curiosity,  do you have a photo? Last year i had some hab. Inter planted with peruvianum. Both set abundant fruit. Potentially crossed.

Joseph Lofthouse wrote:William: I stare a lot at the Solanum corneliomulleri plants to try to answer that question... Half of the corneliomulleri plants this year are descended from the seed that you returned to me. They are the population that has the plant with 10X larger fruits, and plants with huge abundance of fruits. And a plant with wholly purple fruits. And they are early! None of those traits have been noticeable in the S corneliomulleri population in the past. So it seems like they might be hybridized. It's really hard in a species -- that is so genetically diverse to start with -- to identify hybrids based on things like leaf/flower shape.  But then, this is the third successful generation in my garden, and I call that the magical year in my plant breeding efforts, so I don't know how much of the improved growth to attribute to plain old selection, and how much, if any, to attribute to hybridization. I certainly plant in such a way as to encourage natural cross pollination within and between species and complexes. I'm growing a crossing block containing 7 species and 2 families of interspecies hybrids. They aren't necessarily compatible with each other, but I'm certainly inviting genetic exchange between them.

I'm intending to pick the corneliomulleri fruits plant by plant, to see if any differences jump out that wouldn't be obvious in a bulk picking.

This year, I planted patches of S peruvianum, S corneliomulleri right next to each other. I'm really toying with the idea of listing them as Peruvianum complex in my next seed catalog.  A patch of S habrochaites was planted a few feet away. Also nearby were patches of [domestic X habrochaites] and [domestic X pennellii], so perhaps there might be a little back crossing going on as well. At least I'll be watching for it in future years.

I'm wishing that I'd have planted the bulk of the S habrochaites plants closer to the [domestic X habrochaites] plants. That might have encouraged more back crossing to S habrochaites. The rows are only about 24 feet away, but still....

I have a population of S peruvianum that is self-seeding. There are two plants among the volunteers that look like they might be habrochaites/peruvianum hybrids. They may get frozen in a couple weeks unless I dig them and bring them inside. They aren't anywhere near to producing fruits.

Joseph, how large are the 10x fruits? Wondering how they compare to mine. Mine seemed similar to last years.

I may have rubbed some exserted styles in pollen from multiple species as well as bees doing the same last year.

Do you think you will indeed dig up the possible hybrids? Wondering about doing the same. Has that worked well in the past?

This is all very interesting to think about.