[crmauch]

Originally Posted by dfollett

I always assumed fruits from an F1 should be consistent (but then, I am an amateur with not a lot of knowledge about tomato genetics). As I’ve been saving seed, I’ve noticed that in some – but not all – of the F1s of the crosses the fruit from a single plant have varying numbers of seed locules. In some it is either 2 or 3 locules. In others, it is 2, 3 or 4, and in one case fruits with 2, 3, 4 or 5 locules from the same plant. One cross had nothing with 2 locules and everything had either 3 or 4 locules.

There was not a strong correlation between the fruit size and the number of seed locules. Perhaps on average, those with more locules were larger than those with fewer, but I certainly couldn’t guess before cutting into them which would have which. On one plant, the largest single fruit I harvested had two locules while the majority had three and more had four than had two.

I read once back at the turn of the century, tomato breeders tried to progress their breeding programs by choosing a superior fruit. They made no real progress until they started making their selection for breeding on the whole plant (i.e. if the plant has one smooth tomato and the others ridged, the smooth tomato is not going to pass on different genes than the ridged ones.)

Originally Posted by dfollett

Now to my question (I tend to ramble): When I grow out the F2s, is there any expectation of larger fruit on plants grown from seed out of fruits that had more locules than those that had only two like the typical cherry? What about fruit from seed of the 5-locule fruit versus that from the 2-locule fruit from the same F1 plant? Or, will all the fruit have the same potential regardless of the number of locules in the F1 fruit?

I kept the seed separate based on the number of locules and am wondering if it was a waste of effort. I'll have an idea a year from now as I grow out some F2, but I'd be interested in the insights of those of you who might know the answer. Is there is a likelihood of getting to larger fruit at F2 and beyond more quickly by focusing on seed from the fruits with more locules?

I don't believe saving seed by locules will make a difference. Now if you have a plant that consistently has more locules on average than a different plant, that is something to select on.