How many lines should I take to F3?

[Hatgirl]

I am doing two grow outs

• a dehybridization of a commercial F1 that I am finding difficult to source so I'd like to keep it around for myself
• a grow out of a mystery plant that had several traits that didn't match its siblings so is probably a cross between the official label and some other tomato variety. It tastes just as good as the label/parent and is a bit more compact.

In each case, I saved seeds from two different fruit (I remember hearing that it was a good idea to save seeds from multiple fruits but I have no memory of why). And I sowed half of the seeds. So for the commercial one, I am sitting here looking at 30 F2 plants. For F3, should I only pick one plant and continue with that one line to F3 onward? Or should I grow out F3s from lots of different F2s?

Should my plan change based on whether its a dehybridization of a commercial, or a cross grow out?

[bower]

Usually with a cross of dissimilar parents, the F2 generation is very diverse. So it's not unusual to save seeds from several F2 and grow out more than one line, because they're very different (but equally appealing) tomatoes.
There's a second reason for saving seed from more than one, that is as a backup, in case the line you grow forward comes to a dead end and is not what you hoped for. You might lose a key trait and hope to recover it by backcrossing to the F2 (or other generation ) sibling.
Or you might find you have half the traits you want in one F2 plant, and other traits you wanted are in a second one. In that case save both, whether you grow one line ahead or both depends on your plans and resources. You may still find all the traits in F3 from one line, but saving the other seed is a backup.
So although it's a good plan to save backups, there's no need to grow more than one line forward if you have a plant in the F2 that has the qualities you desire. That applies as well to the dehybridization as it does to the cross.

I think with 30 plants, you may well find exactly what you wanted.
I find it hard to evaluate taste from a large number of similar tomatoes at once. Will be interested to hear how it goes.

[Shule]

[mention]Hatgirl[/mention]
I don't know the specific reason that was in mind when you heard that saving seeds from multiple fruits was a good idea, but here are some good reasons to do it:

* Different fruits sometimes have different germination rates.
* If one of your fruits got cross-pollinated, odds are good that the other fruits didn't.
* There might be mutations in a specific fruit that aren't in another.
* More seeds.
* It's fun to experiment.

[rxkeith]

i think you would want to prioritize which of the f2s have what you are looking for.
decide which ones are the most promising, and which ones can wait, and go from there.
how much space do you have to grow out the crosses? the more space, you have, the more
lines you can grow. with my own anna russian cross grow out, it has been hard to choose
which lines to carry forward each year. i still have f2s waiting to grow out, f3s to revisit,
and some promising f4s i want to pursue.


keith

[Doffer]

Here u can find how many plants u have to grow.
viewtopic.php?f=19&t=2059

Its all depending how many genes u want to select for!

[Hatgirl]

Here u can find how many plants u have to grow.
viewtopic.php?f=19&t=2059

Its all depending how many genes u want to select for!

Not quite. If you are breeding for recessives, once you see all the traits they should all appear in the next generation.
Also the numbers there are just the law of averages not a guarantee - just like how if you toss a coin it's a 50:50 chance it will land heads up, but you totally could toss a coin four times and get heads each time, or sow 4 plants and not get a single one with the gene you want

[Hatgirl]

Thanks for the advise everyone! The commercial is a micro so it's full of recessive genes and will probably be pretty stable, so I will save seeds from multiple plants but only continue one line, and keep the others as backups.
The mystery cross - well I will see what happens in the F2! If they are all similar I will only keep one line, if they vary I will see what I like from them!

[Pippin]

Edit: posted this before seeing the latest updates from [mention]Hatgirl[/mention].

It may depend also if you are having a serious breeding project in your mind or if you just want to have a seed source with ”close enough” tomatoes. I used to maintain multiple Fn cherry tomato lines just to have good quality seed source. My lines didn’t segregate that much for fruit size and the fruit color remained the same without any changes. I actually just used the same F2 seeds for several years. Then when I saw something worth saving, I moved to the next generation. Quality wise, some lines lost little bit flavor and crack resistance the further I went. This approach does not work that well with hybrids with complex background, such as Sungold.

It is good to understand little bit which traits are recessive or dominant. For example, yellow or striped tomatoes will very likely keep these qualities in all following generations if present in F1. One can also try to make some educated guesses what can be expected to see based on the fruit shape, e.g. longated tomatoes will likely stay longated, and perfectly round will likely stay round. Slightly oval tomatoes may segregate to round only if the original parents had different recessive fruit shape genes. Many recessive fruit shape genes express themselves slightly even when the dominant form is present too.

[Tormahto]

"How many lines should I take..."

There is no "I" in "we".

We, in this community should be able to help you with some of the growouts.

There is an "Experimental" category in the MMMM swap. Save seeds (and join at your own peril).

[MissS]

We also have a place on the forum where you can offer seeds. Why not offer some seeds and ask for help in stabilizing some of these. There are plenty of people here that enjoy helping to create some new varieties. Just be sure to ask for seeds back of those that turn out well.

[Hatgirl]

Other time constraints I have mean I can't take on the organizational issues around distributing seeds. I also don't participate in grow outs, or swaps. They are great! But not suitable for my circumstances.