Restoring Promiscous Pollination To Tomatoes

[philagardener]

I should think a quick rubbing alcohol dip would be enough to do it. Dilute to 70% with a bit of water (7 volumes of alcohol to 3 volumes of water) - that actually works better as a surface disinfectant than neat - and will dry quickly.

Plastic wrap might be a better surface treatment, and no more wasteful than lots of bits of tinfoil (which gets brittle in an autoclave and is easier to tear/break afterward). Maybe a bulk package of cheap kiddie balloons, lol!

[keen101 (Biolumo / Andrew B.)]

Joseph Lofthouse, 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 relativeto the total number of open flowers on the respectiveinflorescence. Pollination marks are typical brown spotson the tomato flower anther cones, which appear within5 min after a pollinator visited (Fig. 1c). They areexclusively a result of small injuries that are caused bythe pollinators when manipulating the flower for pollenharvest and are good indicators for pollinator visitation,pollen deposition, and thus pollination success. Thepercentage of flowers with pollination marks and thepercentage of fruit set was strongly correlated in oursurveys (Spearman correlation, r¼0.606, P,0.0001;Appendix B). Moreover, pollination marks can be easilydistinguished from injuries caused by other flowervisitors, 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.

[steev]

I wonder whether that would serve as a sort of signal to the pollinators; ie, go find an un-visited flower.

[farmermike]

I've been enjoying looking for potential promiscuous pollination traits in my tomatoes this year. Here are a few interesting specimens.


This is Amethyst Jewel. The stigma is only slightly exserted, but it has an interesting flared tip to the anther cone.


This is an F4 descendent of Sungold which last year had very exserted stigmas. These siblings this year have varying degrees of exsertion.


Above are Black Beauty (left) and Blue Beauty (right) -- high anthocyanin beefsteak types with nicely fasciated, open anther cones.


This is one from Joseph's landrace with an interestingly split anther cone.


I also have some of Joseph's F2 Fern x LA1777 (S. habrochaites). This one has closed anther cones similar to Fern, but the flowers are large and showy and held out above the foliage so that they are visible from way across the garden.


Here you can see F2 Fern x LA1777 growing right next to Silvery Fir Tree (safe to assume this is synonymous with Fern). The flowers on the left are highly visible, the ones on the right are concealed within the foliage.

Unfortunately, despite these potentially attractive flowers, I haven't seen much interest by pollinators. My usual tomato pollinators, bumblebees and carpenter bees, seem to be distracted my radicchio breeding project -- which is currently flowering.     Oh well, I guess I need to work on making my tomato flowers really irresistible!

[farmermike]

Jun 15, 2017 14:34:30 GMT -5 farmermike said:

Unfortunately, despite these potentially attractive flowers, I haven't seen much interest by pollinators. My usual tomato pollinators, bumblebees and carpenter bees, seem to be distracted my radicchio breeding project -- which is currently flowering.     Oh well, I guess I need to work on making my tomato flowers really irresistible!

Haha! I guess I spoke too soon. I just went out in the garden and there was a big old carpenter bee in my early tomato patch. It seemed to be focusing heavily on Forest Fire and Silvery Fir Tree. Then it went and inspected several of the big bold F2 Fern x LA1777 flowers, but turned away and moved on to another section of early tomatoes I received in trades.   

This seemed strange, so I looked closer at the flowers that did not interest the bee.


Here's what I found.


I also realized that, since the weather just today turned hot, and the chicory flowers closed up early, maybe the bees had no choice but to visit the less preferable tomato flowers.

[farmermike]

William, glad to hear about you finding highly exserted stigmas on Blue Ambrosia. I guess it is important (for increased outcrossing) that the stigma becomes exserted very early during flower development. Most of my tomato plants with highly exserted stigmas only do this later when the flowers are fully open (like in my Sungold descendants), so there is probably a high likelihood that the flower has already released pollen while the stigma was still within the anther cone -- and thus pollinated itself.

I did find this one yesterday, where the stigma protrudes well before the flower opens. You can see here that the unopened bud at the bottom of the photo already has an exserted stigma. Seems pretty safe to assume that bud has not released pollen yet, right?


Strangely, it is growing in a clump of mysterious volunteers at the edge of my gravel driveway. I had volunteers in that area last year too, so these must be descendants of those. None of those last year had the exserted stigma trait, and so far only one does this year. Even more strange, is that I have had no other volunteer tomatoes in my garden this year, and these ones on my driveway have survived and are setting fruit with no water whatsoever all summer -- as they did last year too -- which is very unusual in my climate. Perhaps these are just a particularly drought tolerant strain, or maybe there's a leaky water main in that area!

[imgrimmer]

Jul 8, 2017 19:09:04 GMT -5 farmermike said:

I did find this one yesterday, ...

What an impressive flower! The Stigma is very broad, I wonder if it result in a different kind of fruit. Please keep us updated!

[keen101 (Biolumo / Andrew B.)]

Shoutout to Joseph Lofthouse and the Bees that make wild tomato breeding and pollinating 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

[keen101 (Biolumo / Andrew B.)]

Sept 24, 2017 11:02:23 GMT -5 toomanyirons said:

Some observations and questions:

1.)  Quite the sprawling indeterminate plants. Some of the branches have spread out 6-8 feet from the main trunks.

2.)  Blight decimated my tomato crop this year, Joseph's plants were the least affected and I actually question if they even have blight, might just be dieout of the early leaves.  This alone justifies my continued tinkering with crossing of domestics with these strains.

3.)  The two domestic plants are in this mass and are completely dead and dried up from blight at time of photo.

4.)  I noticed very few exerted stigmas or open flowers on any of my tomato plants this year, even strains I specifically saved last year and grew out this year because they showed such traits strongly last year.  I am really wondering now if environmental factors do in fact play a significant role in such things.  Joseph's plants had nice big flowers looking upward but centers not open and no exerted stigmas.  Quite pretty flowers actually.

5.)  I am nowhere near an expert in this subject regarding cross breeding.  What are the chances of successful crossing of Joseph's strains with my domestic strains?  Will they cross both directions or only one way (relative to the parent plant in which I harvest the fruit/seeds)?

6.)  I have been wondering if there are there any toxicity issues regarding fruit from Joseph's strains?  Out of curiosity I tasted the rather unappealing looking fruit from those plants.  By far the yuckiest tomato I ever tasted on some of the most interesting tomato-type plants I have ever grown. 

A fun project and I will expand it next year if I am told there is a decent chance of crossing these into domestics.  I would like to have six plants, two of each of what I had this year of Joseph's strains surrounded by a dozen domestics of different strains from my landrace that are chosen based on open flower or exerted stigma traits.

I'll take a stab at commenting / answering a few of those from my experience this year.

1. I've noticed that sprawling habit in my Joseph's F2 Fern x LA1777. Most similar to the true Solanum cheesmanie that i grew next to them in terms of sprawling habit and leaf shape. Solanum pimpinellifolium was the next closest in terms of sprawling and leaf shape. Solanum peruvianum was sort of sprawling but also has a unique upright growth pattern with elbow joints. Solanum habrochaites was very similar to Solanum peruvianum and hardly able to tell the differences between the two. My F1 Solanum pennellii x domestic hybrid was also quite sprawling / extended. Very much so.

4. The only real tomato i could tell had any bit of exerted stigmas were the F1 pennellii hybrids. They had a unique slightly curved exerted stigma. The Solanum peruvianum may have also had exerted stigmas, can't remember. Actually i think they did. Those were the only two i noticed them on. Joseph's F2 Fern x domestic hybrid had tiny closed up flowers for me. No fruit. Don't expect any fruit. The F2 fern and the S. chilense were the only tomatoes not to produce any fruits the whole season. I attribute this to a combination of being very selective to pollen and not being at all attractive to pollinators or able to self pollinate. Most of the Solanum galapagense also did not produce any fruit. I had one plant i think that produced a few ultra-tiny orange hairy fruits that i collected late in the season, but otherwise all the other plants did not produce any fruits either. They too had tiny closed up flowers not attractive to pollinators and they also may be growing out of their natural island environment and may be lacking some nutrient in my soil. Have a few S. cheesmanie fruits but they are not ripe to collect yet.

5. no idea really. I would think they would most likely be receptive to pollen from other F1 or F2 domestic tomato x LA1777 hybrids since they seem picky to pollen. Perhaps hand pollination is the only way to get fruits on these?

6. To some extent yes, but not enough to worry about i think. The F1 Solanum pennellii fruits i harvested this year were very abundant and plentiful and of a decent cherry tomato size, but tasted awfully insipid. They do have some toxicity from the wild pennellii ancestor, but since they taste so awful you'r not going to be ingesting them anyway and those chemicals are clearly identifiable to the human tongue as to prevent eating. I think as we get to the F2 and beyond in some of these crosses that we will be able to reselct for certain domestic traits like taste and edibility and fruit size while eliminating some of the bad traits from the wild ones. Call it genetic drag if you will, but from my point of view both domestic tomatoes AND wild tomatoes have genetic drag that we need to combine the best traits from each.

My S. pennellii hybrid was the most productive tomato this year by far and the plants grew WELL in my soil and environment. Great start for a breeding project! Exciting to see what this line produces in the coming generations!! I have plenty of seed to share to multiple people of this line. First priority goes to Joseph, but there should be more i can share too! (seeds are not yet packaged yet to be able to send out quite yet).

[Joseph Lofthouse]

Thanks for the grow report.

I grew out a dozen or so plants of Domestic X LA1777. They were all very sprawling. The fruits if very ripe (meaning soft, have fallen off the vine, and changed color from green to yellowish), are sweet enough, and fruity. Spitters before that.

I grew out about 50 F2 plants of Fern X LA1777.

Flower size ranged from tiny to huge. There weren't any open anther cones, though about 5 plants with exerted stigmas. Exercion seems to be environmentally influenced.

It seems to me, that some of the plants had re-established the self-incompatible mechanism, because they flowered like crazy, but didn't set any fruits except where I hand pollinated with a different pollen donor.

Fruit set tended towards very low on most plants. I think, because the stigmas were not exerted, and the anther cone wrapped very tightly around the style. I speculate that prevented the pollen from reaching the stigma, even on self-compatible plants. And pollinators weren't interested in plants that weren't releasing pollen. Some plants produced a decent amount of fruit, so they will be the progenitors of the F3 population, which I expect to be more fruitful.

Segregation for determinate/indeterminate was as expected: About 1/4 of the plants were determinate.

I'm attempting to clone some of the more interesting plants.

An F2 of NOID X LA1777 had very open anther cones.

Th F1 hybrids in my garden lose their lower leaves routinely. I end up with healthy plants growing on the ends of long barren (even woody) stems.

Regardless of whether my tomatoes re-established self-incompatibility, they can act as a pollen donor to domestic tomatoes. The reciprocal cross might not work though.

[keen101 (Biolumo / Andrew B.)]

Joseph Lofthouse, I saw a new word today. Pan-genomics. lol. I instantly thought of you and you multi-species breeding like with the tomatoes (and squash). Like this project and your "Solanum lofthouseii" tomatoes.

P.s. i'm actually planning on calling them that. Apparently it is frowned upon if someone names a species after oneself, but perfectly fine if someone else names it after them. I don't know if the latin naming is correct as i think i'm supposed to drop the "e" and only have one "i", but whatever. I kinda like the e and the double i. Pronounced Solanum Lofthouse-e-eye. haha.

Anyway, yeah i think that's a good name for what you are doing. Pan-Genomic plant breeding!

[Joseph Lofthouse]

Metagenomics said:

The pangenome is the entire gene set of all strains of a species. It includes genes present in all strains (core genome) and genes present only in some strains of a species (variable or accessory genome).<quote>

[steev]

Damn! That sounds rather non-exclusionary, as if there might be genes we ought not to discard just because we don't know their value; that doesn't sound very Big Ag.

[keen101 (Biolumo / Andrew B.)]

Im on the hunt mostly for S. sitiens and S. lycopersicoides. I am interested in tomato flowers with scent. And it would be interesting if flies visit the stinky flowers and if bees like the sweet flowers. I have a lead with a commercial / preservation seed company in chile. If that doesn't pan out i may try my luck with the TGRC again. I need to write a check and send a snail mail to sacred succulents for some S. chilense seeds.

link.springer.com/article/10.1007/s10681-008-9863-6

Adaptation to extreme aridity and soil salinity are evident in S. chilense and S. sitiens (the latter exhibits several xerophytic traits not seen in the tomatoes) and to low temperatures in S. lycopersicoides and S. chilense. All tested accessions are self-incompatible, with the exception of one S. peruvianum population collected at the southern limit of its distribution. Several distinguishing reproductive traits—anther color, attachment, and dehiscence, pollen size, and flower scent—suggest S. sitiens and S. lycopersicoides attract different pollinators than S. chilense and S. peruvianum. The four Solanum spp. native or endemic to Chile provide a variety of novel traits which, through hybridization and introgression with cultivated tomato, could facilitate development of improved varieties, as well as research on a variety of basic topics, including plant-pollinator interactions, abiotic stress responses, and evolution of reproductive barriers.

[keen101 (Biolumo / Andrew B.)]

Jun 7, 2014 6:47:31 GMT -5 ferdzy said:

I bought some seed for Jaune Flammé a few years back that turned out to be quite crossed. Normally I would be "cross" about that, but the results were actually very good. It seems like Jaune Flammé crosses tend to keep the growth habit of Jaune Flammé (about 6 smaller tomatoes in a truss; very indeterminate; highly productive) while picking up the flavour and colour of the other parent. I had some that had a really great classic red beefsteak look and taste and I am continuing to grow these out, as that's hard to find in a smaller tomato. This year will be F4. I am looking forward to seeing what I get - so far it's been pretty stable.

There were also some that were marbled yellow and red, again with a typical flavour for the larger bi-colour tomatoes. I didn't save seed from them, although maybe I should have. I do have a few seeds left from that packet. Maybe I should grow them out next year and see what else I get.

How did these turn out? Smaller tomatoes with the beefstake look might be really cool.