Questions About (Cross) Pollination

[dfollett]

I have a few questions relating to pollinating tomatoes and the possibilities resulting from crossing. These questions flow from results I am experiencing right now from crosses I attempted this summer. I attempted numerous crosses using F4s of a Micro Multiflora cross made by ChrisK and reported on in a separate thread. In each cross, I used the micro as the female and used pollen from several different full-sized and some dwarf varieties to make crosses. As I save seed from each crossed tomato I plant 2 or three to see if they come micro (cross failed) or regular sized (cross succeeded). That makes it easy to determine if the cross took.

Setup to the questions – Most of the time the seedlings are consistent – all large or all micro. In some instances, there will be two large and one small of the three or one large and two small. I haven’t taken them beyond the seedling stage, so I can’t say for sure if the smaller ones are just poorer or slower growing ones that would eventually catch up or are truly micros. Some of the pollen donors are themselves unstable F2 or F3 crosses and some of them with additional crosses on both sides.

1. Question – Is it possible that some of the seeds from a crossed fruit can be crosses and others from the same fruit be self-pollinated?

2. Another question that flows from the above – if you blend pollen from numerous different pollen donors and use that to make crosses, will the seeds in the crossed fruit be from one of the donors or will they be from multiple donors?

a. I know that can happen in the animal world. A female mink can have offspring from two or more different males in the same litter – from matings that were as much as 9 days apart.

3. The above questions are probably only different ways of asking this one question: Are all the seeds in a fruit from a single pollen donor or are many different pollen spores (? – or whatever they are called) needed to properly pollinate the flower with each one contributing to the seeds in the resulting fruit?

[KarenO]

1. Yes
2. Either.

My question, what is your desired outcome? Why use unstable, still segregating male or female parents? Results will be a random roll of multiple genetic Dice no matter what.
. Not sure what the reason would be to work with another breeders tomato before it is stabilized. I assume Chris is aware and supports the idea.
KarenO

[nctomatoman]

Dan, I found the answer to #1 this year just recently. As I enter the world of crossing - using our released dwarfs and thinking outside the box to work toward new and interesting things - I planted a few seeds saved from a tomato that arose after I did the cross. I am using dwarf as female - and potato leaf dwarf makes it even more clear to quickly confirm success or failure.

Two seedlings arose from my three planted seeds of a cross made on to a potato leaf dwarf. One seedling was tall, spindly, regular leaf (success!). The other was squat, thick stemmed and potato leaf (failure).

It was a useful result - of the 20 hoped for crosses, three gave me dwarf seedlings - but instead of confirming failure, I went back and planted 10-20 seeds to see if by luck a few grains of indeterminate pollen made it through. Clearly I was a bit late in getting to these flowers before emasculating - the deed was already in progress, if not done.

[Worth1]

Dan, the end of the stigma of the tomato flower has a receptor for each ovule in the ovary.
Each one of these can match up with a pollen grain and make a single seed.
So in theory the tomato could produce as many crosses as there are seeds.

Go on line and look at flower close up and you can see the many ways these flowers are formed.
It is quite amazing how different these flowers are.

We all had biology in school and we know the difference between twins in animals and humans.
From your comments we all know that out there somewhere there are fraternal twins that have two different fathers.

Now what I would like to know, does the pollen from different tomato verities look different?
In other words can you distinguish pollen from a sungold and some other tomato.

For those of you that may not know.
They can do core samples in old pond bottoms and such and find pollen.
With this pollen they can tell what kinds of plants grew there at certain times in history.

An anti science guy was arguing with me about this and I just gave up.
He simply didn't want to believe there were trees at Chaco Canyon at one time and the Indians cut them all down.


Worth

[dfollett]

Originally Posted by KarenO;502613,

My question, what is your desired outcome?
KarenO

1)I wanted to learn how to make crosses and be able to easily see if they took. 2) These plants are small and can be grown on a shelf throughout the year, 3) they have hundreds of flowers to work with (great for clumsy, big-handed people who ruin more flowers than they succeed with) and 4) very quickly show if the cross took - you don't even need to wait to determine leaf type!

Originally Posted by KarenO;502613,

Why use unstable, still segregating male or female parents? Results will be a random roll of multiple genetic Dice no matter what.
KarenO

1) I made some very intentional crosses with stable varieties for specific purposes, 2) on others I used the pollen I had available, and 3) specifically because the "results will be a random roll of multiple genetic Dice no matter what." Sometimes random is fun and interesting!

Originally Posted by KarenO;502613,

Not sure what the reason would be to work with another breeders tomato before it is stabilized. I assume Chris is aware and supports the idea.KarenO

Don't worry, Chris is aware.

[dfollett]

Thanks for the answer. That was probably a question I could have learned the answer to with just a little research. Asking the experts here is the lazy way to learn.

That explains why some fruits have very few seeds and others on the same plant many more - partial or incomplete pollination.

Also another advantage of the micros - never any question as to who daddy is....

[crmauch]

Originally Posted by Worth1

For those of you that may not know.
They can do core samples in old pond bottoms and such and find pollen.
With this pollen they can tell what kinds of plants grew there at certain times in history.

An anti science guy was arguing with me about this and I just gave up.
He simply didn't want to believe there were trees at Chaco Canyon at one time and the Indians cut them all down.

(Off topic I know): They also used this to know how the climate of Greece changed (originally Oak forests, to what it is now).