Fixing Traits

[VintageNM]

At what point will you have stabilized or "fixed" traits in a variant (assuming you do not get any accidental crosses)? F3? F4? I plan on hybridizing the following this year:

Wapsipinicon Peach X Hillbilly Potato Leaf
Purple Russian X Green Sausage
Riesentraube X Striped Cavern
I'm interested to see the results of each, has anyone done any crosses of these before?

I am also growing and may add these into the mix, as I tend to get carried away!
Black Sea Man
Plum Lemon
Jaune Flamme
Super Bush F1 (Rennee's Garden Seed Pack)
I'd love to hear suggestions....

Thanks!

[lefty_logan]

http://kdcomm.net/~tomato/gene/genes.html

[nctomatoman]

From experience here with crosses, (the Dwarf project), we are finding that it takes into the F6-F8 generation to get the traits fixed. The traits that fix most quickly are when you find a recessive - so in the Dwarf project, if we find a potato leaf dwarf in the F2, subsequent generations are PL.

[Tom Wagner]

Anytime you are trying to get a line to be stable, it is best to have a number of single seed descent populations going at the same time. I don't read many here at TVille following this example but here is a quick example/definition....

"Single-seed-descent " is a method to rapidly fix genes in breeding lines and is commonly used by plant breeders in the northern hemisphere. Once the F1 is grown out, it involves descending one seed per plant each generation. By growing out multiple generations per year it is then possible to advance a population to a genetically stable generation in a much shorter time than conventional plant breeding methods that generally use only one generation per year.

http://www.cropbreedingservices.com.au/

One can actually get professionals to help grow out your segregations for a few years, send the seed back to you as they are near fixed and you make your selections among the single seed descenders.

Advantages of SSD over conventional plant breeding methods:

• Time from cross to release reduced by approximately two years
• The success of crosses can be monitored and selection pressure to populations adjusted accordingly
• More opportunity to select for desirable traits before lines are fixed
• Greater proportion of lines with desirable traits being bulked for yield testing

I do a variation of the SSD by doing a single seed/single fruit descent. That means I can plant one seed or several depending on the space required and test out different sub lines until I find one or more that I like.

If you don't know what traits you want to fix, a strict single seed descent (SSD) allows you to bulk a single seed from each F-2, F-3, F-4, etc. plant and go on and on until you have a serendipitous result. Each year means that you can eliminate one or more of those plants that you bulk a single seed from. If you really like something, you can take a whole bunch of seed from a single plant and plant them out. If it is stable enough for the things you like...a few more generations to get to the F-6/F-8 is usually enough unless you are selecting for a trait that is only expressed in the heterozygous allignment.

The F-1 seed is planted out. The seed from that F-1 is now F-2. This is when I plant a lot of those.........and select anywhere from one to a hundred plants. You save the seed from a single fruit that is not doubled (more likely to be outcrossed) per plant. Plant one seed per plant to get the widest variation to go onto the F-3 seed. Of course, if you have say,plant 17 that is really super...go ahead and plant more of those in a special plot. Otherwise keep the single seed descent going in the other groupings.

I often give sub-names to my F-2/F-3 plants. When I sent out seed of my Gambler's Selection back in 1983 through my Tater Mater Seed catalog, I had gotten back seed from interested folks that favored one over another. My Armendariz Selection of Gambler's Selection was very good for this fellow in California and was for me too when I finally went to California to live and do research. The thing I liked most about the Armendariz selection is that it had a jointless pedicel, compact plant habit, large fruits and flavor....a combination that did not exist in the parents.

To further test a line to determine whether or not it is stable, cross it with one or more lines of OP tomatoes that have a similar or dissimilar trait. Say you have an F-3 plant of Stupice x Green Zebra and it has a regular leaf. Cross it to a Stupice, Pink Brandywine, or some other true breeding potato leaf to see if the cross is stable for potato leaf. If about half of the seedlings are potato leaf then you know the F-3 plant is not stable for leaf type. Same holds for dwarf genes, determinates/indeterminates, etc. Sungold hybrid work can be annoying. Crossing a Sungold to a red will give you some reds and golds in the hybrid, saving the seed to make sure it does not segregate from a gold back to a red can be tough to prove unless you grow a lot of plants from time to time. A simple cross say of an F-4 Sungold x Campari that has gold fruit crossed to a Campari will give you 100% golds if the F-4 is stable for gold color.

One of the fun things that happen when you make crosses of F-2/F5 selections back to one of the original parents is that very cross sets up another dynamic for selection. When I took an F-2 plant of Black Brandywine x Green Zebra and noticed that the fruit were not taking on any stripe whatsoever, I took the pollen over to pure Black Brandywine to make the backcross. The hybrid of the backcross was so stable I thought that maybe if was selfed and not crossed! However I noticed that one plant out of the the siblings had large fruit size, the same coloring of the Black Brandywine, I immediately gave the best F-2 plant the name of Black Snoqualmie. It had none of the defects that show up in the regular BB and better tang. The Black Snoqualmie is an example of rejuvenating an older variety of tomato....keeping most of the integrity but eliminating the defects.

Tom Wagner

[Timmah!]

So it's basically multiple concurrent lines, one from each plant...
At what filial do you start crossing the progeny to combine desirable traits?

[Tom Wagner]

concurrent.....occurring or operating at the same time; "a series of coincident events"

So it's basically multiple concurrent lines, one from each plant...
At what filial do you start crossing the progeny to combine desirable traits?

Sometimes I have concurrent lines within concurrent line, but I am not using the mathematical term -lines-, more like concurrent selection.

One of the poor features of single seed descent (SSD) is that you are not assessing the variability with a single fruit's siblings, but imagine growing the necessary 16 or more plants per selection each concurrent year? It is one thing to have a tray of tomatoes all of which are SSD in a tray of 72 cells and 72 trays of 16 plants each....
72 x 16 = 1152

That represents part of my own personal dilemma...I grow too many plants of too many combinations.
Sure, you could quickly see segregation patterns with more plants per fruit/plant. I for one, do more plants per fruit rather than a strict SSD. I know what I am looking for, know the segregation, know the traits, know the recessives, have heavy handed opionions.....

The beauty of SSD is that you can give each of your neighbors a tray of 72 tomatoes..each plant from a different F-2 etc. and some favorites will be found very rapidly...The next year instead of one seed per 72 plants...you could do 6 plants per twelve F-3 etc. plants and finally down to say 32 plants per two F-4 plants. and 72 plants per one F-5 plant.

The last question about filial generation and when do I start crossing again is ludicrous....since I can not wait to stabilize by itself...I am constantly crossing this F-1 with this F-2 and that F-1 to a 24 parent hybrid and so on. I quickly see traits that I want and bring it into the fray again and again. That is what is happening with the OSU blue tomato...a blue cherry crossed with a striped blue salad tomato crossed to a green/blue woolly tomato crossed back to the original OSU blue. I am working with the ultimate variety maker-----cross-overs with meiosis. How are meiosis and mitosis different? MEIOSIS is the complicated process of chromosome seperation. MITOSIS is the copying process. I am speeding up the evolutionary potential by not just copying the OP threshold.

Meiosis used repeatedly, crossing hybrid to hybrid to hybrid to F-2 to hybrid is novel to tomatoes, normally selfing 95 % of the time. Variety development by accidental crossing creates more diversity.

Meiosis_vs_Mitosis can be looked at in a different light if you think this way: OP varieties are like asexual reproduced organisms...the whole process of making seed is akin to cell reproduction, exact replicas. But by keeping the tomatoes in a constant flux of hybridization and segregation with re-hybridization----mutation like changes occur frequently, hence--cross-overs---and a limited amount of selfing to fix the unique modification is dancing in front of your eyes!

To Err Meiotically is Human but for a Tomato to err Meiotically is Heaven!

Tomatoes having optional or alternative sexual and asexual cycles seem to be the best targets for research on the evolution of varieties. A good number of wild tomato relatives are OBLIGATED OUTCROSSERS , however, cultivated tomatoes transported great distances as a single fruit had to become OBLIGATED INBREEDERS, owing to the isolated nature of being the founder tomato, self or perrish! Enter the Heirloom era:no longer are tomatoes grown one variety to a field or garden...but are collected one plant at time but added by the dozens varieties, each recognizable by name or unique features.... ..pressed into close proximity, and obligation to oneself is thrown out the kitchen window....miscegenous pairing of tomato varieties creating the new kids on the block, grown with a reverence unheard of before and bandied about like eye candy to the dispossessed. An odd thing happened...tomatoes are supposed to OP...so chance hybrids are taken to the asexual route of OPing "La Diferencia" within a few generations of selfing.

Enter the myopic meiosiscator with piscatorial lures; fishing for tomato genes like seines along La Seine, forcing tomatoes to more than Heinz 57.
Same on same begets more of the same. Different on Different begets "I live the Difference!


Tom Wagner ...ignore the puns from the punditry

[Timmah!]

"The last question about filial generation and when do I start crossing again is ludicrous....since I can not wait to stabilize by itself..."

Having not read beyond the current thread & having not made any assumption about when you decide to begin crossing, I don't see why the question was ludicrous. Perhaps the propostion itself of waiting- considering your awareness of the nature of your process- is ludicrous, but no temporal &/or results-oriented target was implied in the question.

Thanks for your reply

[Tom Wagner]

LudiCROSSity

Relating to ridiculous irony, odd juxtapositions causing chuckle or grin

Very inside joke here. I directed the term to my juxtasupposes of making crosses with the full intent of getting the F-2 seed from a least one fruit but going on to making several crosses, thus the ludicrossity of making more crosses before the said plant is stable or fixed in the traits. No sense making sense out of something if I can make nonsense out of it first.

-------

What did the OP tomato plant say to the hybrid plant that had too many traits?

TRAITOR!

The hybrid tomato plants yelled back at the OP tomato--Oh, go self yourself!

The OP tomato in turn yells back, "Oh what? Your Mommy get cross with your Daddy?"

The Hybrid tomato says to the OP tomato..."You must be a tree tomato...no branches in your family tree!"

"Oh, yeah?" retorts the OP tomato. "Look at you, all high and mighty reaching to to top of your tomato stake..you must be of indeterminate origin!"

The Hybrid snidely replies, "I am of patented lineage by the Monsanto people!"

OP plants says sadly, "Well then Roundup Ready Eddy...I hope a Glyphosate resistant bindweed crawls up your vine and chokes you!"

Hybrid tomato bellows, "Hey, you are kinda short and bushy....are you a Republican?"

OP tomato leers up and down the hybrid's vine....No, I am not a Bush, I'll have you know, I am a determinate independant"

The Hybrid tomato grimaces at the sight of Tom Wagner walking towards the tomato garden with his crossing equipment.

OP tomato plants screams, "Oh my God, Tom is gonna cross the two of us!"

Hybrid tomato...."Lord, Help!"

Tom Wagner

[Timmah!]

Ok, I gotcha. Do you step into your test environment & immediately immerse yourself aware of the composition of it all, or do you have to study a journal of some sort to keep up with everything?

[Tom Wagner]

Do you step into your test environment & immediately immerse yourself aware of the composition of it all, or do you have to study a journal of some sort....?

Each year is a little different than the last. I have only two plots planted outdoors in the gardens and one series of benched potted tomatoes outside one of the greenhouses. I have one garden that is mostly blue tomato selfing lines with my best late blight res. line Skykomish. In that plot I remember each plant so I won't need to resort to my pedigree bood and field map.

Another plot consists of priority lines of hybrids of blues, Green Zebra OP and hybrids, Skykomish hybrids, and an assortment of extreme novelties. The pedigree map in this plot will be looked at for nearly every cross.

A CSA greenhouse is planted with mostly my tomato lines and it that one there is over 125 different clones/varieties. They have been setting fruit for a while now and I will start the breeding work soon there. Waiting to make sure there are plenty of fruit setting for the CSA and a single fruit for me to extract self/OP seed. I am waiting to make crosses there standing up rather than down on my knees crossing the first clusters of flowers.

Most of my tomato plants to be transplanted are still in the greenhouse waiting for the weather to warm up. It has been very cold and wet, temperatures down in the uppper 40's at night and even now...nearly 1:00 in the afternoon it is only 52. Too cold to grow a good plant and too cold for pollination. We have not had a day reaching even 75 all Spring! The long range forecast indicates that come Summer time, June 25th, it may reach 77.

What tomatoes will be used the most as pollen parents this year?

Skykomish, Green Zebra, and Blue/Green Woolly Zebra. The last one will fairly easy, the selected selfed lines that are very woolly and super blue leaves and stems are already in the various locations. As soon as I see the blue fruit developing, I will start some contingency crosses and when the fruit ripens on certain lines for the colors of flesh to manifest themselves.....I will step up the crosses again but with the most colorful ones.

My crossing days will be starting as soon as I get some more field planting done. I hope to make about 100 crosses per day once I get started. I will make an effort not to just start crossing everything with one pollen parent, but study the pedigree map and make conscious matings.

Tom Wagner

[Timmah!]

Wow, that's alot of work. Good luck to you in your endeavors.

[johno]

Originally Posted by VintageNM

AI plan on hybridizing the following this year:

Wapsipinicon Peach X Hillbilly Potato Leaf
Purple Russian X Green Sausage
Riesentraube X Striped Cavern
I'm interested to see the results of each, has anyone done any crosses of these before?

I am also growing and may add these into the mix, as I tend to get carried away!
Black Sea Man
Plum Lemon
Jaune Flamme
Super Bush F1 (Rennee's Garden Seed Pack)
I'd love to hear suggestions....

Thanks!

I like that you think outside the box. That's how you find the most curious things. I'm especially delighted at the thought of WP x Hillbilly PL.

I suggest you do keep more than you think you need for potential crossings, because it's unlikely the plants will cooperate with your itinerary. You might have to wing it, depending on which plants have flowers at the right stage concurrently.

[VintageNM]

Thank you Tom, I truly appreciate your answers. You are one of the reasons I joined TV. Be warned I will pick your brain about SSD in the future!

Johno-

WP X HBPL is the only crossing where I am looking for a particular outcome. I want a larger fuzzy tomato that is meatier and looks more like a real peach with red highlights, the outcome should be interesting. I planned for timing issues already this year by starting seed at 2 week intervals for different plants figuring that one plant of a both varieties would be on near a similar schedule. (Plus I can always save pollen from one or the other and wait!)

The PR X GS I am particularly interested in if I can get a brown sausage with the acidity of the GS for making sauces...but we'll see!

RS X SC I just want to see what kind of F1 these make, should be interesting.

I'll end up doing a lot more crosses than planned, especially since I'm container planting this year and my 30' X 100' plot will be totally ready next year giving me tons of space to grow out F1s. All the late rains and cold weather made it hard to do anything with! Hairy vetch will be my friend this winter!

I'll keep you posted.