F2 Question

[rjs55555]

I have not tried to croos any plants yet but was curious. If you save seeds from a single F2 tomato will all of the offspring be the same or does each seed get polinated individually? Could you get different colors, leaves etc or would you need a couple of f2 tomatoes to get different varieties.

Sorry for the newbie question.

Thanks,
Randy

[TZ-OH6]

Each seed is pollinated individually, and because tomatoes have paired chromosomes, but the ovule and pollen have only single chromosomes any trait whose gene is heterozygous (mixed dominant and recessive) will be split up/mixed at random in the pollen and ovules. Any expressed trait that is recessive will be homozygous and fixed from the point it is expressed onward, so once you have a potatoleaf plant the potatoleaf form will always show up from self pollination.


If you look at all of the F2 plants here within the square, those cells that are not highlighted will give a mix for at least one of the two characteristics in the F3 seed http://tomatoville.com/showthread.php?t=11700

To determine what the mixture would be in the offspring of one of those F2 (f3 seed) simply take the combination (e.g. gf+/gf+, r+/r) and make a new square out of it [gf+,r+ and gf+r x gf+,r+ and gf+r]

[Tom Wagner]

Randy writes....

I have not tried to cross any plants yet but was curious. If you save seeds from a single F2 tomato will all of the offspring be the same or does each seed get pollinated individually? Could you get different colors, leaves etc or would you need a couple of f2 tomatoes to get different varieties.

I noticed that this is your first post. I would imagine that if you read enough of the messages on TVille, you may get closer to the answers you need.

I cannot assume that you will ever cross your own tomatoes, however I thought of a great example of a cross that you may wish to make someday.

I crossed Tiny Tim flowers with pollen from Stupice. I made this cross a few years ago because my gardening friend sells these varieties plus others for her customers that want early tomato varieties here in the PNW. These plants were in the greenhouse so I made the cross as a contingency for further variety development.

Tiny Tim is a dwarf tomato with smallish 3/4 to one inch red tomatoes with a regular leaf. Stupice is an indeterminate potato leafed red tomato with fruits 2 inches and a bit larger. All of the F-1 plants were regular leafed, indeterminate red tomatoes with a diameter of about 1 and 5/8 inches.

This year I put out F-2 plants that had several features quite easily seen as transplants: Some dwarf. about a fourth of the seedlings and a fourth of those seedlings that were dwarf were potato leafed. Fully 3/4 of the seedlings were tall plants and again, one fourth of those tall plants were potato leafed. What did I save out of the seedling tray? I saved a few of the dwarf plants, both regular leafed and potato leafed. I also planted a few indeterminate regular and potato leaf seedlings. Therefore, I have about four kinds of plants out in the gardens, greenhouses, and fields. I am saving seed from a minimum of 4 plants because I want to put into my inventory; twp clones that look like the original Tiny Tim and Stupice, but more importantly, the two contrary ones that are the dwarf potato plant and the indeterminate regular leaf plant.l

Since I am putting a priority on selecting a dwarf potato leaf version, the F-2 seed that I just extracted is from such a plant. It has 5 locules which indicates a closer affinity to Stupice. It also was very early compared to either original parent of their days to harvest 50 and 60 days reportedly. Your question as to saving seed from an F-2 as whether the offspring will be the same...the answer if fairly much a yes on the one I just described because the recessive genes of dwarf and potato leaf are true breeding now. There may be a little variation on some other characteristics for a few more generations. But if you save seed from a regular leaf/indeterminate plant, you may find that there is still segregation going on with most of those types of plants and that the segregation could still occur for generations.

Because of my dwelling on this F-2 plant that is both dwarf and potato leaf and will be forever true breeding for those traits, I've decided to name it after the parents -Tiny Tim and Stupice- as "Tiny Bit Stupid"

Tom Wagner

[rjs55555]

Thank you for the info. I am sorry for the newby question.

Tom,
I like the tomato name.

I was thinking of Crossing a Red Robin with a Black Cherry to try to get Black tomatoes on a tiny plant. And also a moonglow with either a red robin or a Tiny tim. Still thinking through it and hoping to get a good cross.