Pollen Collection with Limited Space

[mwamsley]

In trying to find a way to have many male donors in a limited space, I'm giving this a shot this year.

I'm growing the males in small containers and packing them together. I figure that once I collect and store the pollen, the plant can be discarded. The major drawback in doing this is that I don't get a chance to evaluate the male for being true-to-type. Or do I? They might fruit in their small containers. The other drawback is that they are thirsty.

16 Males; 13" milk crate, 2.75" x 8" pots, big-box square tomato cage shortened to 44". Heavy hand pruning. Daily watering. They are competing but most have their crown about the same height. The ones that don't are pulled to the edge.



Storage on calcium chloride (CaCl₂). A piece of a cotton is stuffed on top of the CaCl₂ and stored in my freezer. This should store for 6 months. Coincidentally, I have plenty of CaCl₂ on hand because I use it as a brewing salt! More info: Storage life of tomato pollen.



This variety is said to be parthenocarpic. I'm emasculating it's first flowers to see if it produces fruit, or aborts.




-Mark

[dfollett]

Thanks. I'm learning how the pros do it. I did something similar, but crossing indeterminates onto micros during the winter when I didn't have room to grow the indeterminates. I grew the indeterminates in 4" cups and collected pollen as they produced flowers.

I read the article about pollen storage life and it created a question. It said something about poor pollen setting fruit with few seeds before it was completely non-viable. I sometimes see plants with plenty of fruit but very few seeds in each fruit. Is that a result of poor pollination, is it genetic, or either/both? Is there a simple way to tell?

Also, I am often growing indoors with no pollinators and no wind. I only buzz flowers when I want to collect pollen to make a cross. Other than that, I don't help the pollination. My logic is that by doing that, I am also selecting for plants that pollinate easily with no help. Is that faulty logic or is there something to it?

[mwamsley]

I'm all for growing as small as possible. I probably could have gone much smaller.

Doing it the way I'm doing it is probably overkill, though it's helping me keep organized. More than likely, when I need to make a cross, I can use a fresh flower. In theory we can easily share pollen with each other using the postal service.

Yes, the article is interesting in that fruits continue to set with old pollen, but wouldn't form viable seeds. You would think that there's probably a maternal genetic component to poor seed set with old pollen. Do all varieties allow for fruit set with old pollen? I know that in many parthenocarpic tomatoes, they'll set fruit without any pollination by means of increased hormones, not some partial sexual process. And it's mostly the result of single gene.

A few things missing from the paper: Do I need to pre-dry the pollen before freezing? Can I store below 0C?

You logic seems fine about buzzing flowers. As mentioned above, I emasuclated some flowers of reported-to-be parthenocarpic tomato. I did this before any pollen was available and bagged them. If they're parthenocarpic, they should set fruit. I would think you could try this with any tomato to see if there is an improved fruit set component.

I grew out Reisetomate with hopes of emasculating and crossing, but I couldn't discern a normal anther cone or stigma. The fasciated stigmas were fused at the base, then go Medusa. A complete mess! But I was able to shake out some pollen.