An interesting breeding possibility

[bower]

Hi Dar,

I am delighted to say I have also gathered together quite a few early and cold tolerant varieties to trial in 2013. Glacier and Kimberley are on my list of small fruited earlies, and they sound very promising. I grew Stupice and Moravsky Div last year, and found them both to be great producers, setting full trusses in spite of cold nights. Stupice was vigorous and a very healthy plant. MDiv was earlier and more compact.

Another small fruited early variety I received in Heather's swap is Alaska. There wasn't much comment on the taste, but tolerance of windy conditions is mentioned. This might be relevant to the gene you're looking for to close stomata in adverse conditions.
I also found some old packets of Early Cascade F1, which was my standard years ago, it was a great tasting tomato with disease resistance breeding, so if I can germinate the old seeds I will grow it and perhaps cross with something. If not I'll look for the dehybridized version next year.

There was an idea in another thread, to grow an early standard like Stupice every year and use it as a reference clock for the DTM of others (ie Stupice + n days). I like that idea as a reality check on DTM's in different places and seasons.

Al Kuffa and Danko are two early determinates I'll be growing this year with larger fruit. AK is described as cold tolerant with a nominal DTM of 50 days and 3-6 oz fruit. My earliest (rated) indeterminates with larger than 4 oz fruit will be Break O Day (60-70) Siberian Red (55-70) Azoychka (60-70) Pink Berkeley Tie Dye (65-80) Pale Perfect Purple (65-80).

There was a very interesting thread going about earliness, last winter. I have a file somewhere of the notes and links to reading about cold-hardiness and earliness genetics which I will dig out soon and review. I seem to remember reading that 2 of 3 earliness genes were pleiotropic if not linked with small fruit size, and I think precocious flowering gene is one of those. But the third gene which is on a different chromosome doesn't affect fruit size. I reckoned the early larger fruited varieties might have that desired gene but may never be quite as early as the small fruited ones.
As regards the parthenocarpy gene, it may not be as bad as it sounds, as I believe I read it is simply due to an increased level of gibberelins/auxins which allows fruit to form even when not pollinated. Originally I thought they were 'seedless' as in sterile, but this doesn't appear to be the case. They set fruit with seeds when conditions allow it, but seedless fruit in extreme cold or heat afaict. I didn't get my hands on any of these varieties yet (Cold Set, Siletz and Oregon Spring are varieties with this gene, among others).
When I get a chance to find that file again, I'll post some links.

[Boutique Tomatoes]

I've trialed a lot of the cold tolerant varieties mentioned trying to deal with the weather fluctuations we see here in the spring. (Bower, I know I've grown both Cold Set and Siletz; I'll check to see if I still have seeds if you like.)

I'm impressed with what I'm reading so far and thanks to Dar for sharing the plans and thought process with everyone. I grinned as I read through thinking that Dar in Alabama will be working on cold tolerance while I'm in northern Wisconsin and am interested in tropical varieties.

I am curious about the jointless pedicel as I seem to recall seeing that mentioned in a number of breeding discussions recently. This isn't something mentioned in variety descriptions, is it something typically found in modern hybrids?

[Fusion_power]

Jointless is a trait that was introgressed from S. Cheesmaniae about 40 years ago. It is a single gene variant that results in a single long peduncle extending to the fruit. There is really only one advantage to this gene. When you pick a fruit, the stem automatically separates. This is useful when bulk harvesting tomatoes because there are no stems sticking up from the fruit that puncture other fruit.

DarJones

[Boutique Tomatoes]

My curiosity was if jointless was likely to be found in modern hybrids, like Big Beef or Carolina Gold for example. It's not something I've paid attention to in the past, but I can see it's value.

It was just a thought, wondering about using hybrid parents to get more desirable genes in play.

[bower]

Originally Posted by marktutt

I've trialed a lot of the cold tolerant varieties mentioned trying to deal with the weather fluctuations we see here in the spring. (Bower, I know I've grown both Cold Set and Siletz; I'll check to see if I still have seeds if you like.)

Mark, if you find the seeds I'd love to grow them, thanks. I would like to see how the parthenocarpy trait plays out and compare with others.

Here are the notes and urls to research on parthenocarpy from my reading files last winter, mostly gleanings from abstracts. I'm sure the full papers contain more info so if anyone has read them I hope will share it with us:

parthenocarpy and cold weather fruit set:
http://www.actahort.org/books/200/200_16.htm
controlled by a single recessive gene. high GA in flower ovaries
additive effects of three recessive genes:
http://www.springerlink.com/content/v67u238260nx4548/
QTL's:
http://www.ncbi.nlm.nih.gov/pubmed/18231773
http://www.ncbi.nlm.nih.gov/pubmed/19700496
http://www.ncbi.nlm.nih.gov/pubmed/19619340
GMO parthenocarpy: re seedless.
http://www.ncbi.nlm.nih.gov/pubmed/16371162
cultivars with parthenocarpy:
[PDF] Genetics of the parthenocarpy for tomato varieties 'Sub-Arctic Plenty','75/59'and 'Severianin'
cultivar Nadja: parthenocarpy due to a single recessive gene:
http://www.springerlink.com/content/j46459731p800218/
cultivar Severianin : two recessive genes
http://www.springerlink.com/content/v272m3443w220t17/
in line RP 75/59: three recessive genes
http://www.springerlink.com/content/v67u238260nx4548/
E. Vardy, Dvora Lapushner, A. Genizi and J. Hewitt
linkage of one gene to diageotropica (dgt) located on chromosome 1 L site 152, dgt: "Plant habit prostrate due to reduced gravitropic response; growth retarded; stems and leaves droopy; cotelydons concave. Roots grow horizontally rather than downwards."
and a second gene to yellow verescent (yv) located on chromosome 6 L site 34
Light yellow-green leaves, paler at growing point, which has velvety appearance.
yv 2 yellow virescent
vel^2, vel1^2 Smaller, irregular bush; short internodes; soft yellow, velvety growing points shading to normal green below; smaller than vel.
yv -- yellow virescent Pale yellow-green; virescent foliage. several male sterile alleles are also described.
here's a full text piece of work on Severianin:
http://www.plantphysiol.org/content/122/2/471.full
here's one on determining parthenocarpy in the F2:
http://www.sciencedirect.com/science...04423887900112

I haven't re-read any of these to check or clarify my notes, but it looks like there are adverse phenotypes associated with several of the genes for parthenocarpy. This seems to be typical of other cold tolerance traits as well, afaict, with a few exceptions. So it's not surprising that many of the available cold tolerant earliest varieties are described as "semideterminate" or smaller plants. Maybe being smaller is part of the strategy to survive cold....

[Heritage]

One of the best threads I've read anywhere! Great info, thanks!

Steve

[Fusion_power]

Seed are accumulating rapidly now. I have the requested accessions from TGRC. I received a pack of PI 120256 from ARS today. I also have identified the below varieties as potentially cold tolerant from seed I already have. The seed from Andrey should arrive next week. Tatiana is also sending me some varieties that she thinks may have some cold tolerance.

Kotlas - Small early red potato leaf
Bellstar - Jointless and was developed in Canada with a degree of cold tolerance
Wheatley's Frost Resistant - has cold tolerance, but seems oriented toward late season rather than early spring
Glacier - Small early and productive with some cold tolerance
Stupice - Small early and productive with some cold tolerance
Siberian - Small early and productive with some cold tolerance
Siberia #2 - Small red potato leaf with stress tolerance
Tastiheart - my selection that survived 22 degrees F April 7th 2007
LA2006 - ft gene for setting fruit at low temps.
PI 120256 - One research paper says it has high cold tolerance
Lyuda's Mom's Red Ukraine - thick walled oblate red slicing tomato
Moskvich - Small red tomato but may have some cold tolerance
Russian Bogatyr - Regular leaf irregular red
Winter - Small red, unknown cold tolerance

From Tatiana:
Sasha's Altai - This is commonly reported to be a cold tolerant variety

In addition to the above, I have about 70 breeding lines from TGRC that involve wild species. Tests should quickly show which have cold tolerance.

I have one further thought about the breeding work as documented in research literature and directed toward developing tomatoes for cold climates. The work that has been done to date was oriented toward producing a small fruited plant that grows very fast and matures fruit in a short season. In other words, to change the number of growing degree days to fruit maturity. My efforts will be oriented toward reducing the temperature value of a single growing degree day. In other words, to produce a tomato that actively grows at lower temperatures than normal.
DarJones

[Diriel]

Keeps getting more and more interesting.

[Dutch]

Originally Posted by Diriel

Keeps getting more and more interesting.

It sure does!
Fascinating!
Dutch

[bower]

Dar, that's a very worthy objective.

I've heard good things about Moskvich - one of my farmer friends here grew it every year.

[Fusion_power]

I've started planting seed. Won't be long now! (what the skink said when the little boy picked him up by the tail!)

DarJones

[bower]

That's exciting, Dar! Can't wait to hear some of your results.

Are you planning to do the cold tolerance tests on these ones?

[Andrey_BY]

Dar, I marked some of my tomato varieties as "rather cold tolerant".
I consider "a rather cold tolerant" a variety which can stand a T about 0 C at least for a short time without being damaged and frozen.
Real cold tolerant tomato varieties like Saraev's varieties can stand temperatures below 0 C.
Common early varieties like Moskvich are not cold tolerant, but you can check it by yourself of course.

[Fusion_power]

Thanks Andrey, I am spreading a very broad net to find as many traits as possible that contribute to cold tolerance. I expect to have 90% or more that fail completely. If I get 3 or 4 with significant tolerance, I will be satisfied.

DarJones

[Wi-sunflower]

If anyone wants them I have several varieties that might be helpful.

Early Cascade -- discontinued variety. I have grow-outs at F-5 or higher.

Oregon Star -- parthenocarpic variety with "goose egg" sized fruit I would say are more or less in the heart category, very meaty.

Cowberian -- seeds originally purchased from a commercial source as "Siberian" but were not. A grower out in the PWN knew they weren't Siberian when he grew them out and he renamed them "Cowberian" in honor of my State, Wisconsin. Tho they were "wrong seed" he continued to grow them and has shared them with others in the PNW as they seen to grow well there.

Carol