Selecting Which Fruit to Save Seeds From

[Solanum315]

Probably a stupid question but liberal arts major here.....

In the process of stabilization of a particular line, and also assuming that there is no cross polliniazation, does it matter what particular fruit you save seeds from on one particular plant?

Case in point, I got an accidental cross with Black From Tula and a small commercial Roma from the Philippines that was one of many called "Native". I am growing out F2 now and there are a number of saladette sized tomatoes with some interesting variations in color but my main objective is to stabilize a beefsteak or two. Out of 8 plants, one of them came up beefsteak. On that one beefsteak plant, I selected the largest fruit to save seed from.

The heart of my question: would 20 seeds from this fruit necessarily be any more likely to produce large fruit in the next generation than 20 seeds from, say, the smallest fruit on the same plant? I kinda suspect not but would appreciate a more science-y answer.

I recognize also that the catfaced fruit is sometimes indicative of a megabloom which some believe are more likely to be crossed due to a more pollen receptive pistil shape....

[arnorrian]

It shouldn't matter. All the fruits on one plant have the same DNA. Only the inner part of the seeds has different DNA, which is set before the fruit starts forming.

[NarnianGarden]

There are those who swear that consistently choosing the most desirable fruit eventually leads to healthier, more productive, disease-resistant and tasty straits. Others say that no matter how moldy / diseased the fruit, as long as the seeds a re viable, the genetics are the same and the mother fruit doesn't matter.
People probably have made their own experiences and drawn their conclusions... I have not really saved many seeds so I don't know what the results would be in a few generations.

[slugworth]

I save
1. the 1st to get ripe
2. the biggest
3. any mutants that show up.

[Tormato]

I'd save seed from 2 fruit and not mix the seed, assuming you are not bagging blossoms.



While there is a slight chance (1/20?) of one of the fruit again being crossed, there is a rare chance (1/400?) that both would be crossed. And next year, start seeds from both fruit.

[Hunt-Grow-Cook]

Since the question was about selecting for size and nothing to do with its potential for being crossed or the quality of the fruit when harvesting seeds.....Yes. Save seeds for the traits you are looking for. Continually do so over x amount of years until you have isolated or stabilized the traits want.

"The researchers wanted to learn how the tomato genome has changed since the fruit was first domesticated, and then transported around the globe and bred for commercial purposes. They sequenced the genomes of 333 varieties of red tomato, 10 varieties of wild tomato and 17 modern commercial hybrids. They studied the change in the tomato's size over time and found that the increase in tomato size since its domestication had involved a two-step process. At first, selection for size, the primary purpose of tomato breeding, resulted in the creation of cherry tomatoes. Big-fruited tomatoes appeared later. "

[maxjohnson]

Someone here told me to not save the first to get ripe, because they are more likely to cross since there are less blossoms to go around early in the season. So now I don't save from the first ripe one anymore.

[Lee]

A couple different issues being mentioned here, so let's separate those.


Since you are growing the F2 generation, you should pick the plant that exhibits the traits you are interested in and save seed from that.


1. Since it is still unstable, any seeds you save from any fruit on that one plant can still exhibit variability. So there should be no difference in the probability of finding the same desired traits in the next generation from any fruit you save from this plant.
In my opinion, save as many seed from as many fruit of this plant as you want. Combine them, or keep them separate makes no difference genetically speaking.


2. Others have brought into the conversation the chance of cross pollination from bees. If you don't have pollinators or don't ever see them on your plants, then these concerns are not relevant. If you do have pollinators that you've seen on your plants, you should only save fruit form plants that were set when pollinator activity was low or non-existent.


Finally, just because you don't see a trait you're interested in with your other F2 plants, does not mean that it isn't possible. If the genes that are responsible for the larger fruit size are recessive, they can still show up in later generations.
I had a yellow (recessive trait) fruit show up in the 5th generation of my red fruited F5 growouts. So if you've got space to spare, you can also growout some of your "non-beefsteak" F2s that had other traits (flavor/productivity) that you liked to see if you can get the beefsteak size in the F3.


Hope that helps and good luck in your growouts!


Lee

[bower]

Those are nice looking fruit, Scott.
As others have said, the genetics are the same in all the fruit on the same plant, with the possible exception of a pollinator cross. In my garden the bees are less interested in tomatoes early in the season - fewer are out and they are looking for something with nectar as well as pollen (tomatoes have just pollen). So I think the number of pollinators at the time of year is the rationale behind saving seed from first (and last) fruits.
If there are lots of pollinators, or even if not, it is well worth it to save from more than one fruit and keep them separate. I've had mixups happen (elves? gnomes? brain damage?) in spite of my best efforts, so several times I've been really glad that I had more than one separately saved.

It is true that you might find another beefsteak line by growing out the smaller fruit, but you might have to grow really a lot of them to find a nice sized beef like the one you have in hand. I would grow plenty of those beef seeds next generation, and you may well end up with more than one line that are good enough to continue on. Chances are good you will get black, brown, pink as well as red, so grow plenty and pick the tastiest ones.

[Solanum315]

Thanks, all. Good advice. I am thinking of dedicating all my tomato growing space to the F3 generation next year so that I have as many selection options as possible. Would be exciting to see some turn back to black as that is my favorite color aesthetically. If anyone wants to play around with some F2 or F3 seeds, shoot me a PM. Since my last posting I have taste most of the saladette type plants. Most did not leave much of an impression but one in particular had a very nice sweet flavor and soft flesh so I think I will save seed from that plant as well as the beefsteak.

[bower]

Plant at least a half dozen to be sure to get one black (assuming it's there, which is still likely at F3) Did you get some blacks in the F2? I would hope so.

Unless you're totally fed up with saving seed (yes, it does happen!) I think you're on the right track to save any others that have taste or any other outstanding trait you desired. I have a binder full of seeds I may never grow out, but who's to say. Tomato seeds last a long time. Priorities and space available can also change, and I've never regretted those extra side lines, I've enjoyed the ones I grew (or most of) and even if I didn't like the result, at least I learned something.
Tomato breeding, a lifelong pursuit with unlimited supply of surprise endings...

[Solanum315]

Originally Posted by bower

Tomato breeding, a lifelong pursuit with unlimited supply of surprise endings...

Yes, and the surprise endings are usually a lot better than say, Game of Thrones Season 8.....

No black tomatoes at F2. Hopefully will get a few at F3 although I am very fond of pinks as well and that is what I mostly have now.