Author Topic: Frost and Cold Tolerant Tomato Breeding including epigenetic and regular genetic  (Read 7124 times)

Garrett Schantz

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Flower color in Joseph's picture is consistent with  Beta orange genetics, that is also found in wild relatives.
tangerine t is the other common orange gene, found in domestic tomatoes.

There is an explanation for why the orange would appear from plant parents that weren't orange.  Beta is only expressed in a red background.  So if one of the parents was yellow or bicolor afaik, Beta could be present but would not be expressed.  In an F1 cross with a r/r red the F1 will ripen orange-red.  So you can see Beta is present even in B/- but only if the base color  is red.    Some recent work suggested Beta is an allele of the same locus as oldgold and ogc oldgoldcrimson.  The Beta allele results in a high content of Beta carotene instead of lycopene.

Tangerine orange is a different locus and works very differently.  It is recessive, so t/- F1 will not show any orange.  However it can be expressed in any background, red, or yellow or bicolor afaik.  The flowers of a t/t tangerine plant will have an orange anther cone and the petals as they dry turn peach orange instead of straw yellow.  The intensity of color does vary depending on the background and possibly some modifiers, but it is recognizable if you're looking for it.  Tangerine orange fruit is rich in prolycopene, and low in beta carotene.  So they are nutritionally different as well.

There are other orange genetics (Delta, apricot) but they are rare by comparison.  Apricot has almost white flowers.  Delta fruit is more like a shade of red than orange.  I haven't encountered either of these in orange fruit I've grown.

Don't suppose the flower here could be Apricot? Found it on one of my mix of F1 pimpinellifolium crosses. I think there were a few others like that. They are all dead now though.

Also posting a strange flowering - whatever it was. The plants with these small buds eventually formed real flowers.

I am going to recreate my initial cross with pimpinellifolium - habrochaites. I am assuming that I had some variation in the F1 because I used over 30 fruits - and their seeds, screened for anything off-type from the parent. Being different species, I could have lost initial genetic information in that original cross due to only saving seed from a few F1 crosses... Next time I will grow most of the hybrids outdoors where I have room for them.

Also, if I can reproduce the white flowered types, that would be pretty nice.

(Suppose I got everyone a bit off topic!)
« Last Edit: 2021-07-07, 12:32:24 AM by Garrett Schantz »

Steph S

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Wow Garrett, those are truly gorgeous.  8)  Very cool.  There are pics of apricot flower type at TGRC if you want to compare.
That habrochaites anther color is also really pretty.  :)

Guessing genetics by flower color is a little tricky, because the color changes as pollen matures and is shed.  So you need to look at flowers in different stages.  When I get a chance I'll start a thread and try to get some decent pics to show the recognizable types that I know.
The tangerine orange anther cone is a deep orange color as soon as it opens. Petals start yellow but then fade peachy pale orange as they begin to age.   
Flowers on beta, red, bicolor or pink fruited start either a warm yellow or light orange that quickly deepens to orange as pollen matures and is shed.
Flowers on yellow or gf (black or brown) fruited start a greenish yellow but may also turn a warmer yellow to orange from the pollen being shed by the time they're done, however that is slower than the development of orange color in the red or Beta type.

If the orange in your habrochaites crosses is tangerine, that could also turn up unexpectedly from non-orange parents because of t being recessive and not expressed at all as t/-.

The conclusive way to determine if Sungold is Beta or tangerine, would be to cross it to a red and a yellow fruit and check the progeny: In a red cross, F1 Beta will ripen orange-red, and 3/4 F2 will be expected to be orange or orange-red.   F1 tangerine will be just red, and the 1/4 ratio expected for orange fruit in F2.  In a yellow (or bicolor? afaik) cross with Beta, you should get no orange in F1 or F2, while tangerine will show up as yellow-orange or light orange in F2 at the 1/4 ratio.

Roland

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Very interesting hypothesis that the orange of Sungold Beta is carotene.
The orange in the flowers in tangerine is indeed missing.
I have already made the cross between Sungold and Sungreen. Sungreen is a green tomato and contains yellow(rr) homozygous.

I can make another cross with Sungold x Dorada (Yellow), Sungold x Clou (Yellow) or sungold x Sunviva (Yellow) and of course another cross with a red tomato.

The F1 with a cross of a yellow tomato will possess:
Sungold RR,BB x Yellow rr,--
Rr,B- and yet also show Red and Beta. As a result, I think the phenotype of SunGold x yellow tomato should also be orange?


Steph S

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Indeed, Roland, I don't know if Rr is enough for the B/- to show up.  Look forward to hearing your results.

Garrett Schantz

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Wow Garrett, those are truly gorgeous.  8)  Very cool.  There are pics of apricot flower type at TGRC if you want to compare.
That habrochaites anther color is also really pretty.  :)

Guessing genetics by flower color is a little tricky, because the color changes as pollen matures and is shed.  So you need to look at flowers in different stages.  When I get a chance I'll start a thread and try to get some decent pics to show the recognizable types that I know.
The tangerine orange anther cone is a deep orange color as soon as it opens. Petals start yellow but then fade peachy pale orange as they begin to age.   
Flowers on beta, red, bicolor or pink fruited start either a warm yellow or light orange that quickly deepens to orange as pollen matures and is shed.
Flowers on yellow or gf (black or brown) fruited start a greenish yellow but may also turn a warmer yellow to orange from the pollen being shed by the time they're done, however that is slower than the development of orange color in the red or Beta type.

If the orange in your habrochaites crosses is tangerine, that could also turn up unexpectedly from non-orange parents because of t being recessive and not expressed at all as t/-.



The images that I posted were of my F1 habrochaites x pimpinellifolium. Sadly no longer have them - had too many pots, thinned a bunch of plants out and used them to obtain F2 seed for this growing season.

The F1 types were columnar in terms of growth.

The white flowered type only had that color on a single plant, I used two wild species - wasn't that fun to manage / tie up a stick.

Hopefully I will find the white color again. Along with any other fun genetics.

The F2 plants will probably have a wide mix of different fruit colors. Should be fun.

Roland

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SunGold F1 is giving a lot of pollen. About 10 times more as my domestic tomatoes.

Today I made the crosses:
Sunviva (Yellow) x Sungold F1
Dorada (Yellow) x Sungold F1
Clou (Yellow) x Sungold F1
Primavera (Red) x Sungold F1
Read Pearl (Red) x Sungold F1
Sungold F1 x Sunviva (Yellow)
Sungold F1 x West Virginia 17B (Red beef)

The flowers used had 1 or 2 petals open and I removed the pollen from this.
Is it true that these are still too young for self-pollination?

Steph S

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I didn't see a thread about crossing techniques so I just started one, Roland.  I often use flowers that are just starting to open, as long as the petals still look white I believe the flower is still immature.