First Time Hand Crossing

[M.SeanF.]

A couple of weeks ago I attended Fred Hempel's tomato breeding workshop. I'd heard Fred speak at the Heirloom Festival before so I had high expectations, and I wasn't disappointed.

The hands on demo was exactly what I needed. I've now tried several crosses, and so far none of the blossoms have aborted. I can't wait for the fruits to swell so I know whether or not the crosses actually took. If any produce fruit I'll post photos and details on the parents.

So far I've used Japanese Black Trifele (PL) as the female for each of my attempts and all RL males so I can tell if any potential F1 seedlings are actually the result of self-pollination.

Sean

[crmauch]

Glad to have you among us tomato breeders.

My tomatoes got started late, then had a problem (I think I had 'bad' potting soil).

Decided to spend the year fallow (which will allow my soil where I mostly plant tomatoes to have less pathogen).

[M.SeanF.]

Are you planting a cover crop in the meantime?

[Allisa]

Recently I also tried to cross pollinate tomatoes. I learned how to do it on youtube. The very first try was difficult. It took me a few times to feel comfortable to do it. I love the process. My fruits are very small, but they're getting bigger.

Now, I have a question on how many seeds of F1 I need to plant next year to see if the cross is successful?

[Al@NC]

Allisa, you may have to grow many! There are a few things that breeders do such as cross a regular leaf and potato leaf (host) and so then early on you can if you regular leaf (since potato leaf gene is recessive)... There is lots of reading on crossing! But basically if you determine before you cross the traits that your looking for and can identify those traits (dwarfism is one) at seedling stage then you won't have to grow out everything...

Al

[nicollas]

F1 seeds : few (your case)
F2 seeds : many

[Fred Hempel]

3 or 4 plants should be enough. Since all should be uniform (if all true F1). If they look like the female parent, you might have not have removed the anthers soon enough.

There have been times when I have only gotten 1 or 2 seeds from a cross. I grow them, and they are usually F1, and you really don't need more than 1 plant (in theory).

Originally Posted by Allisa

Recently I also tried to cross pollinate tomatoes. I learned how to do it on youtube. The very first try was difficult. It took me a few times to feel comfortable to do it. I love the process. My fruits are very small, but they're getting bigger.

Now, I have a question on how many seeds of F1 I need to plant next year to see if the cross is successful?

[M.SeanF.]

Originally Posted by Allisa

Recently I also tried to cross pollinate tomatoes. I learned how to do it on youtube. The very first try was difficult. It took me a few times to feel comfortable to do it. I love the process. My fruits are very small, but they're getting bigger.

Now, I have a question on how many seeds of F1 I need to plant next year to see if the cross is successful?

I'm still waiting for my fruits to start swelling. So far none have aborted and I'm taking that as a good sign.

As far as how many F1's you need to grow, I would say at least two, even if space is limited. That way if the plants are identical, but different from either parent, you can be pretty sure the cross worked. However, if you used a hybrid as one or both of the parents your F1's will be more like typical F2's and genetically varied.

[Allisa]

Thank you all for your input and guidance!

So, if I understand right, if I've crossed heart shaped variety (mother plant) with round/oblate shaped (father/donor), should F1 produce round shaped tomatoes? Both varieties have regular leaves and both are indeterminate, different color (antho and pink).

And another question: on the label what name should go first, mother variety or father/donor?

[Fred Hempel]

Your fruits should be swelling after 5-7 days. Sometimes it takes longer if the pollination was particularly inefficient.

Fortunately, crosses that did not take usually abort after a couple of weeks. If you see a yellowing of the stem at the abscission zone, your cross is likely on the way out.

Originally Posted by M.SeanF.

I'm still waiting for my fruits to start swelling. So far none have aborted and I'm taking that as a good sign.

As far as how many F1's you need to grow, I would say at least two, even if space is limited. That way if the plants are identical, but different from either parent, you can be pretty sure the cross worked. However, if you used a hybrid as one or both of the parents your F1's will be more like typical F2's and genetically varied.

[M.SeanF.]

Originally Posted by Fred Hempel

Your fruits should be swelling after 5-7 days.

One of my crosses worked! When I checked today, one of the blossoms I hand pollinated
has swollen to the size of a pea. I used Orange Russian 117 as the pollen source and Japanese Black Trifele as the female. With this heat I'm surprised I have any fruit setting.

[Allisa]

Originally Posted by M.SeanF.

One of my crosses worked! When I checked today, one of the blossoms I hand pollinated
has swollen to the size of a pea. I used Orange Russian 117 as the pollen source and Japanese Black Trifele as the female. With this heat I'm surprised I have any fruit setting.

Hi! Congrats! It would be interesting to follow your results! Very tasty and beautiful parents (trying to imaging possible variation at F2).

I checked mine and also got some swollen, some of them didn't make, even though they were a size of a pea, I think because of our heat.

I used Lucid Gem as a pollen and Orange Russian 117 and Rosoviy Myod as a females.

Have tried to get some pollen yesterday and today from 10 am to 6 pm periodically a few times a day, got none, too warm, heat makes a pollen sterile. Our cool days are in the past for this season. But I hope, I will get enough to try and play with next season. I've put some cover on the top of some tomatoes (imitating a roof) and will check if that will make a difference and I will be able to get some more pollen this season.

[crmauch]

Originally Posted by M.SeanF.

Are you planting a cover crop in the meantime?

Yes!

[crmauch]

Originally Posted by Allisa

Have tried to get some pollen yesterday and today from 10 am to 6 pm periodically a few times a day, got none, too warm, heat makes a pollen sterile. Our cool days are in the past for this season. But I hope, I will get enough to try and play with next season. I've put some cover on the top of some tomatoes (imitating a roof) and will check if that will make a difference and I will be able to get some more pollen this season.

You can also "harvest" the anthers and dry them inside. If you store them in the refrigerator, you can use the pollen for weeks.

[Fred Hempel]

Excellent. Missed this when you first posted.

Originally Posted by M.SeanF.

One of my crosses worked! When I checked today, one of the blossoms I hand pollinated
has swollen to the size of a pea. I used Orange Russian 117 as the pollen source and Japanese Black Trifele as the female. With this heat I'm surprised I have any fruit setting.