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 Heuer 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.

[PaulJ]

I have to agree with what Joseph has said.

Last year I grew some "medicinal plant" varieties that are known as frost tolerant
I sprouted them in a cold windowsill with average ambient day temps (10-15C) and low-ish night temps (4-10C)
they didn't get potted up after 3 inch, they grew great as soon as put out and never got "checked" by the cold ut they seemed to lose their frost tolerance.

Another variety that were sown later straight into warm soil got a few checks but were  much more frost tolerant, although Id never grown this before so its harder to know

All anecdotal but It makes me wonder if maybe at least one of these genes is a one way switch, cold or frost tolerance but not both.