diversity in f1 in crosses from hybrids

[swampr]

Using f1s as parents in new crosses is an interesting concept for developing new and different lines. Understanding that some f1s have more heterosis than others, and choosing crosses with sungold as a parent, as an example:

In a cross between an f1 and a stable o.p., how many individuals should be grown in f1 to assess the results and capture the possible outcomes?

In a cross between two different f1s, how many individuals should be grown in f1 to assess the results and capture the possible outcomes?

I realize that there are many traits to analyze, so there may be no simple answer to this question. I'm just looking for general guidance based on experience or theory.

[tz]

I'm growing out Kosovo x [Lime Green Salad x Green Sausage], and where as the F2 ratio for double recessive is 1:3 plants for a simple cross, finding dwarves was much more difficult with this hybrid cross, I don't have the numbers but it was somwhere from 1:10 to 1:20 plants (I'm sure someone has the theoretical ratio handy). From 18 growouts (non dwarves) there are two with the multiflora trait, from Lime Green Salad, but no determinants. I should also note that unlike with simple crosses where you will get all combinations of the parent genes within a single fruit from a single F1 plant, with a multiple [hybrid] cross you have to save seeds from more than one 'F1' plant to get all of the genes.

Seed saved from two F1 plants
Plant 1--Kosovo x [Lime Green Salad x Green Sausage] = dwarves in the f2
Plant 2--Kosovo x [Lime Green Salad x Green Sausage] = no dwarves (unfortunately this is the plant I grew out and saved lots of seeds, so this year I'm growing out more F1 plants

[jcm05]

I am gonna bump this hoping for further discussion as I am interested in hearing others' opinions on it. I have often wondered this as well and was under the impression that the F1 would be consistent irregardless of one or both of the parents being a hybrid and simply seeing more diversity in later generations.

[frogsleapfarm]

The F1 hybrid "(A x B) x C" is called a 3 way cross, and will segregate in the F1 generation because the gametes from the (A x B) parent will segregate. There will be even more variability in the F1 from the double cross (A x B) x (C x D). When growing out such crosses I usually plant 4-6 F1 progeny. This doesn't come close to capturing all the genetic variation in the F1, but its usually all the space I can afford.

[swampr]

thanks, i have as many as six of sixteen crosses i made last year. the matrix diagrams are especially helpful. i cant wait to see the results and will let you know my observations regarding diversity. i saw some diversity last year in f1s that jtcm gave me which were made from f1s.

[rammstein]

i have collect seeds of unknown F1 hybrids (determinate) from fields of industrial sauce tomato. For example: how can i use this F1 as parents in cross with pure line of dark tomatoes to try to obtain dark tomato with determinate plant?

[rammstein]

Thank you for your answer, this is just what i have think to do, but explained very well and with very clear words. This year i collect seeds and the next year i start attempts of crossing.

[swampr]

I have seven f1 plants from the cross sweet quartz x sungold. Six look and taste very much like sungold, and one is red. I also noticed that one of the orange cherries is pear shaped.

I also have a size differentiation in f1s from sugary x prudens purple, most are larger, about the size and shape of purple haze and a minority are smaller, a little larger than black cherry. The color of the smaller ones is a very nice deep pink and the larger ones is much more muted. photos to come.