Frost and Cold Tolerant Tomato Breeding including epigenetic and regular genetic

[William S.]

I like red tomatoes fine, and yellow ones, and green ones, and bicolor ones, and orange ones, and fruity tomatillos, ground cherries, and tomatoes with new flavors like Brad Gate's Amethyst Cream. So I suspect I will like many of the new flavors Joseph finds for us but still eat some ordinary red ones too. I even like the ice cube flavored ones taco bell chops up and serves on their tacos.

[Lauren]

As always, I started my tomatoes in regular garden soil, without bottom heat or supplemental lighting. As usual, some croaked. Every year I start them in a similar way and plant out under wall-o-water in March or April. Whether epigenetics or genetics, they seldom die in the spring any more. Those that do I simply replace.

I selected the first to come up, the subset that got secondary leaves while still in dim light (sunny windowsill, no supplemental lighting), and the best of those are now in my garden under milk jugs. Even with snow on the ground they're not complaining. One of the six is easily twice as tall as the rest and I'll be keeping an eye on it. Those six will be my seed tomatoes this year. Two of the other plants have been eliminated--one nearly died when it didn't get watered for a couple days, and the other was covered with aphids in the greenhouse.

Last year I was given a handful of plants. They had a very small survival rate under the same conditions. I think I ended up with fruit on two out of the ten. I was given two tomato plants this year. One croaked in the greenhouse, the other is out under a wall-o-water and getting frost damage even there.

Once I have the spring thing settled, I'll start working on autumn frost tolerance. I have noticed that the plants are much hardier than the fruit. The first frost of the season might not even touch the plants but the fruit bites the dust.

[William S.]

Currently watching seedlings germinate in cool soil. Solanum peruvianum, S. Pimpinillifolium, and S. Penelli  x domestic have won the germination race.

[Chance]

Joseph, do you like acidic flavors in your tomatoes also, or more just sweet and umami?

[Joseph Lofthouse]

Joseph, do you like acidic flavors in your tomatoes also, or more just sweet and umami?

I dislike bitter tomatoes. Anything raw, with nasty bitter red-lycopene flavor is close to unpalatable for me. In domestic tomatoes, I pretty much only tolerate yellow or orange tomatoes.

In the wild tomatoes, I am selecting for high ummami, fruitiness, lack of bitters, aromatic, and sweetness. (I'm selecting against red fruits.) People are describing them as guava, tropical, mango, grape, fruity, fermenty, etc... Flavors that might be more typical of physalis: ground cherry, cape gooseberry, etc...   

[William S.]

I've been trying to hand my toddler yellow tomatoes to see if I can get him to eat them. This morning he made a positive comment about how juicy the store bought cherry tomato I handed him was. Still didn't really eat it. Just bit it then rejected. Wanted it though.

[Lauren]

That reminds me of another idea I had once. I suspect just growing plants next to each other that epigenetic influence can occur from chemicals leached into the soil.

One year I grew a whole patch of my purple stalked corn. That year and the following year after (maybe two) the grass weeds turned a heavy red shade. It did not seem like a coincidence. Obviously they couldn't have been influenced by pollen. It made me wonder if grinding up dessert adapted plants like yucca and spraying it on as fertilizer could help produce a more desert tolerant domestic crop like corn.

Many years ago I was growing lemon thyme as a groundcover in with the raspberries (bad idea--it choked them out) and for the next couple years I noted that the raspberry leaves had a yellow edge just like the thyme. Again probably a nutrient issue, but interesting nonetheless. It was ONLY the plants closest to the thyme that were affected.

[William S.]

Starting my tomatoes in the normally unheated greenhouse this spring. Been unplugging the fan and plugging in a tiny Heater at night. Been interesting to see which species germinated first. A little worried about one night coming up in the forcast. Low of 29 F. Not sure if the heater can handle that. Might get nervous and bring them in.

Curious though if it affects their epigenetics to keep seedlings relatively cold.

[reed]

I start mine in  an unheated cold frame. It's positioned against the south wall of the house, the back and floor are black, a few milk jugs of water take up the extra space.  Hasn't really been much of an issue this year but there have been many times tomatoes sprouted & survived in there when temps at night were intermittently below freezing. It isn't even all that well sealed, I throw a blanket over it on very cold nights but again that hasn't been an issue this year. Maybe I should have started them in February. 

I find this epigenic thing a little hard to swallow but I'm intrigued. The premise being that environmental or other factors  can trigger the same genes to configure themselves in different ways?

[William S.]

Yep, basically as I understand it the epigenome is a system of regulatory switches that turn on and off genes and these changes can be heritable for a couple generations.

[William S.]

During some recent cold nights I took most of my tomato starts inside. Save two I left out just for curiosity. One survived a pimpinillifolium directly in line with my small heater. The other a potato leaf froze back badly. Perhaps it will resprout.

[reed]

My garden is full of volunteer tomatoes right now, mostly the pimpinillifolium crosses I think.

I'v noticed in some years a dramatic difference in how the early volunteers respond to late frost but we haven't been below 50 F for quite awhile and don't really expect to be so guess there will be no volunteer frost tolerance trial this year.

[William S.]

Reading through Tom Wagner's Forum. Somewhere he said that Norelco Tomato was his best frost tolerant tomato of many. Google failed me on finding any mention of it because of Norelco razors.

[Diane Whitehead]

I thought if anyone had it, Bill Minkey would, but he doesn't have it listed.

[Dominic J]

Epigenetics make a lot of sense to me, actually. If a plant is subject to cold temperatures while small, it might accumulate coumpounds or grow in a way that makes it less fragile to cold damage. It's likely a trade-off, the plant will be smaller, stunted growth and all, but would be able to resist cold damage better. While the same clone, in a heated greenhouse, would dedicate all resources to growth, yield. I mean, it's pretty well-known that taking greenhouse plants and bringing them outside without acclimatization will be very stressful to them. Plants grow adapted to certain humidity levels, temperature levels, UV levels, etc., and if grown in a stable environment and just instantly switched to something else, shock and death can occur. I've seen this a lot. And there's a lot of pages on "hardening off" tomatoes.

I'm also convinced genetics play a large role as well, though. Genetics is like owning a winter coat or not, and hardening is getting used to lowering temperatures and thus knowing to put it on before going out.

Perhaps tomatoes could be bred to be frost tolerant without needing to be exposed to cold, but the mechanism for that would probably be an allele that just tells the plant it's cold even when it's not really cold, triggering that cold-response with little to no stimulation, so that if cold does happen, it's ready, even if it had little reason to believe it was coming (figuratively, of course plants don't "think").

My grandfather and I have sown tomatoes in fairly cold conditions (~6C), and other than slowed/delayed growth, they did fine. Frost is another thing, though. I had 1 plant that seemingly survived the first fall frost, a few years back, and it was a hybrid, so the reason it survived while the others of the same variety didn't is possibly non-genetic (though assuming that it wasn't bred from double haploids, that variety could also have had some genetic variation on untested traits such as frost resistance).