Breeding dwarf tomatoes podcast (Craig LeHoullier and Patrina Nuske-Small)

[William Schlegel]

This is my little OSSI collection:

Banana Toes (dwarf)
Big Hill HX-9
Cherokee Green
Dwarf Bendigo Moon
Dwarf Brandyfred
Dwarf Desert Star
Dwarf Fred's Tie Dye
Dwarf Galen's Yellow
Dwarf Gloria's Treat
Dwarf Kelly Green
Dwarf Orange Cream
Dwarf Purple Heartthrob
Dwarf Saucy Mary
Dwarf Sunny's Pear
Hamsonita DXXM Tomato Clade
Honeydrop
Rosella Purple (dwarf),

The only ones I have tried previously are the two Joseph bred. All of them are dwarfs except Honeydrop, Hamsonita, Cherokee Green and Big Hill.

I have a cross between a non-OSSI microdwarf Aztek and a F1 Big Hill cross starting to form three or four tomatoes in the basement. Would be easy with one exserted parent to do what I did with Blue Ambrosia in my 2017 garden. Allow free bee access and daub on pollen. Then save and grow a lot of seed from the exserted parent. Big Hill could be that parent. Could do an OSSI only grex with Big Hill HX-9 as the mother pretty easily just by devoting a crossing block to it for a few years. Though I was thinking mainly just one OSSI parent for crossing. Could be a fun Grex though! Also, potentially could make an all dwarf grex. 

I have a few non-OSSI dwarfs and got a few more to try in 2022. Utyonok is a new to me dwarf that isn't OSSI. From Russia originally. I was wondering the other day which of my tomatoes are Russian and which Ukrainian. Just made me sad wish everyone could just get along and garden.

Another thing I want to know about the dwarfs in my collection is how many of them are like Krainiy Sever (also Russian) and keep their fruit off the ground nicely. I thought growing them in different years that Krainiy Sever did the better job than Payette but when I grew them side by side last year, I thought them about the same in that feature. I don't think it is a universal feature of dwarfs at least not uniformly though because of other genes or whatever which may regulate the sturdiness of the plants, the fruit load, etc. Sounds like Geranium Kiss has too heavy of a fruit load and needs staked despite being dwarf- also a new to me dwarf.

[Joseph Lofthouse]

If the definition of "dwarf tomato" is vines less than 18" long, then I would classify Hamsonita as a dwarf. Big Hill isn't much larger.

[William Schlegel]

Intriguing! I would include the rugose leaves and the sturdy stem in a definition and Craig says they can get about three or four feet tall for him. Very few tomato plants if any get "big" in my garden I think because of the shallow soil, so I really had no idea Hamsonita and Big Hill didn't grow larger for other people. They seem pretty "normal" size in my garden. Though I think it is possible that the small Hamsonita plant I grew and abused in 2021 may have kept its fruit off the ground but it didn't have the full dwarf traits of rugose leaves and sturdy stem. Didn't do that great after it froze and came back though! Not much did in that isolation garden. Not the best place to put the everything else garden. Worked ok for Payette though in 2020. It is kind of hard to water and freezes easier over there. Hasn't had any sand addition either. I should just direct seed that garden maybe with short season stuff.

My own line that I have been calling Mission Mountain Sunrise or MMS one of its big deficits is it tends to let the fruit lie on the ground. I crossed it to Big Hill and have now grown out the F1 over the winter but have crossed the cross to a micro dwarf called Aztek. Might not be the best cross for my goals but it would be nice to have a dwarf version that keeps the fruit off the ground. I am sort of planning a cross with Dwarf Gloria's Treat for that reason. I want an early exserted potato leaf dwarf bicolor with blue blush that keeps the fruit off the ground- a lot of why I want those particular traits is for it to be the mother of subsequent crosses, but it would be fun on its own.

[nathanp]

I have a few dwarf tomatoes that get to 5 or more feet tall.  Wherotokowhai and Uluru Ochre both got over 5' last year, with a couple of plants reaching 5.5'

Rugose leaves and sturdy stem are definitely distinct traits.  If you haven't grown one of them, it is difficult to explain it until you see them in comparison to all non-dwarf tomatoes.

[Patrina Nuske-Small]

Good idea.

I have seeds of about 62 dwarfs so I'll grow one of each this year and see which have exerted stigmas.

I can suggest that Summertime Green may have exerted stigmas, it certainly always did here in Australia where I lack pollinators being interested in tomatoes hence I was lucky to to get 2 or 3 tomatoes per plant 😏

I gave up growing that variety which was disappointing because it's so delicious!

Patrina

[William Schlegel]

I've been wondering what pollinated tomatoes in Australia?! I get native bees in the genus Bombus in Montana USA and have been thinking alot about habitat enhancements this winter.

[Patrina Nuske-Small]

I've been wondering what pollinated tomatoes in Australia?! I get native bees in the genus Bombus in Montana USA and have been thinking alot about habitat enhancements this winter.

When I lived in the suburbs of Adelaide I never had an accidental cross, nothing seemed to visit tomato flowers other than thrips 🙄  But now that I live in rural New South Wales I see an occasional blue banded bee, and they do like tomato flowers.  Even so I've only noticed one accidental cross in 10 years.  But I don't save seeds from fused-blossom catfaced tomatoes in order to avoid any accidental crosses, which was important for me as a seed seller of dwarf project varieties. I now leave seed-selling of project varieties up to others, and I just enjoy eating the fruits with their tasty seed gels intact for a change 😅

I'm curious whether catfacing is allowed or avoided for promiscuous breeding projects? 🤔

Patrina

[William Schlegel]

Catfacing is fine when searching for natural crosses. However, in my gardens it typically only comes from large fused flowers which happen before the Bombus are active so I would still expect little crossing.

The most natural crosses so far observed from my 2022 seeds came from a F2 exserted stigma potato leaf plant in a very dense planting of mixed tomato varieties and species. The first test planting produced two crosses out of 13 plants.

Ultimately enhancing natural pollination chances is just a total reversal of the rules for avoiding them and still it may result in 10% outcrossing if you have the proper bees.

Joseph famously is trying to transfer the obligate outcrossing trait to domestic tomatoes. That would result in nearly 100% outcrossing (plants are rulebreakers so it is never going to be perfect but I don't know if it would be 98% or 99.9999%) but it only works with other tomatoes with the same system.

Ultimately such a system would not work without effective pollinators such as the genus Bombus.

Also if my isolation was good enough say 150 feet or 46 meters with Bombus attractive native plant plantings in between I could save pure seed with very little outcrossing even from very exserted stigma tomatoes in a system with very effective pollinators.

In my gardens I've been trying to both set up crossing blocks and do hand crosses. I do this because I spend a lot of time in the field at my job as a botanist during summer just gardening on weekends and I have had more consistent success with hand crosses inside the house or greenhouse. Last year I had the best success yet with hand crosses and made about eight some with multiple successful attempts. Also potentially the worst success yet with crossing blocks, I set up five and so far have one success. The fact seems to be that some tomato species and varieties are more difficult to work with than others. Results are mixed over time. I tend to collect pollen for hand crosses on a pollen spoon some people use an old sunglass lens. I saw one video on youtube where they showed that you can physically scrape the anther instead of buzzing it. That might be something I can try with my poor pollen donors. Also reverse crosses might be necessary in some cases.

I crossed my Mission Mountain Sunrise F5 with Dwarf Mochas Cherry last year. The cross was difficult and I got only one successful take. I thought the resulting tomato had maybe 1 viable seed and a lot of what I assumed to be aborted crud. A phenomenon I did not expect from a domestic x domestic cross. 60 tiny seedlings emerged from that crud- still waiting on true leaves. I intended it to be MMM x DMC but I only got it to take as DMC x MMM as a deliberate hand cross. I also set it up hoping for natural crosses MMM x DMC and I don't see one yet, only potato leaf so far like MMM but I am still waiting for all true leaves to emerge.

[nathanp]

I've been wondering what pollinated tomatoes in Australia?! I get native bees in the genus Bombus in Montana USA and have been thinking alot about habitat enhancements this winter.

Native solanums in Australia

There are native solanum species to Australia, apparently, so  there are bee species equipped to pollinate related species.

[William Schlegel]

Native solanums in Australia

There are native solanum species to Australia, apparently, so  there are bee species equipped to pollinate related species.

One question I have is to what extent are tomatoes self and or cross pollinated simply by wind? Then when it comes to bee pollination it wouldn't have to necessarily be buzz pollination. What about micro bees climbing inside of the pollen cone? A Midwestern tomato breeder on Facebook once said he had a pollen robbing bee species that would cut in to the anther cone.