Joseph's Tomato Experiments

[joseph]

Frequently I want to post a photo of something that is happening with my tomatoes, but it doesn't fit in with any of the ongoing threads, so I've been skipping the post. I'm starting this thread as a handy place to keep a journal of what's going on with the tomatoes in my garden.

Over the past few years I have been working on a few tomato breeding/selection projects.

I started out in 2009 and 2010 by trialling hundreds of varieties of heirloom and modern hybrid tomatoes: Looking for anything at all that would produce fruit in my garden before frost. Most of them were spectacular failures! Brandywines and beefsteaks self-eliminated very quickly. I don't like providing the labor to pick cherry tomatoes, so they were mostly culled except for yellow pear and Sungold. I was mostly saving seed as bulk lots. Any variety that produced well got dumped into a common fermentation, and mixed with everything else. I did a little bit of selection for frost/cold, because about 10% to 50% of my plants get killed by frost every year, so the most susceptible got eliminated.

In the 2013 growing season I did a frost/cold tolerant trial in collaboration with FusionPower. He provided seeds from varieties that are known for cold or frost tolerance. I found one variety Jagodka, which is quite susceptible to frost, but it grows robustly and fruits quickly in spite of the cool nights. It ripens every fruit in spite of the short season. [Google: "Cold tolerant tomatoes, right down Joseph's alley."]

One thing that we learned from the trial, is that I should be focusing on determinate tomatoes because they are more productive earlier in the season. I suppose that my plants had already shown me that, because my bulk seed had ended up being mostly determinate varieties. In the bulk seed collection this fall, I'm intending to do careful screening to only select for determinate plants.

I do a little bit of frost tolerance testing each year. One of these years after I get some of the other breeding projects further along, I'm intending to make some crosses to screen for better frost resistance. I grew a flat of tomatoes this year that survived a two day long snowstorm without visible damage. Many plants had already been culled from the flat due to previous radiant freeze damage.

Another thing that I noticed during the frost/cold tolerance trial, is that the two varieties that were the most productive were also highly attractive to bumblebees. I'm speculating that they set fruit earlier and more reliably because they were being better pollinated. The flowers shed a dust cloud of pollen when jostled. So that triggered the idea for the breeding project I expect to work on for the next few years: Developing a landrace of tomatoes that are promiscuously pollinating. I'm hoping that will allow me to spin the genetic roulette wheel more frequently in my garden, and lead to quicker development of tomato varieties that really thrive in this area. It will also lead to my garden being full of hybrid vigor. I won't have to suffer through the inbreeding depression that seems so commonplace among the heirlooms that I have grown.

Part of my motivation for pursuing promiscuously pollinating tomatoes is that I think they will do a better job of acclimating to late blight. Rather than throwing one highly inbred variety at the problem, I intend to throw a field of tomatoes at the problem, with each plant being genetically unique and diverse. Then those plants that are most tolerant can share genes readily with each other. It might be many different traits working together that provides the best tolerance. And not just a single tolerance gene. To further this project, I am collecting wild tomato genes, and crosses with wild tomatoes. This year I'm mostly expecting to grow seed, so that I can have gobs to sacrifice to testing.

Last summer I made a few hybrid crosses between Jagodka and varieties with open flower structures. I grew out the seed over the winter and collected F2 seed this spring. The final variety to produce seed is ripening now in plenty of time to grow it out this year. The other two crosses already have F2 plants growing. Some of the crosses were with determinate mates. Some were indeterminate. This summer I intend to screen for determinant plants with open flower structures.

Last fall at the farmer's market, a lady asked me about the taste of my tomatoes. I finally had to confess: My tomatoes taste horrid. I decided after tasting lots of gaggy tomatoes that I like yellow and orange tomatoes better than red tomatoes. Therefore this spring I started another breeding project to develop tomatoes that are pleasing to my taste buds. I expect that they will end up being orange or yellow. I'm expecting that I will mostly use the orange/yellow tomatoes that I planted this spring as pollen donors to some of the F2 plants -- with determinate growth and loose/open flowers -- from the promiscuous pollination project.

One of the F2 Hybrid tomatoes is a cross: [a yellow/red indeterminate beefsteak with open flowers X a determinate pollen donor]. Perhaps I'll be able to find what I'm looking for in one of the offspring: yellow/orange fruit, open flowers, determinate plants.

If I'm interpreting what I'm seeing properly, it looks like:

Yellow fruit is ____
Open flowers is recessive.
Determinate vines is recessive.

I love working with recessive genes, because once I isolate a phenotype, then it is fixed until the plant cross pollinates with something that doesn't carry the recessive gene.