How does one choose seed that will breed true?

I thought if I bought organic, open-pollinated or heirloom seeds, the resultant seeds from those fruits would breed true the next year/ Especially tomatoes.

Can anyone tell me how to distinguish those from the hybrids on the package?

I want to save my seeds for future years but I expect my Brandywine to be a Brandywine and not a cross from another variety.

I think others on the board would also like to be enlightened.

I think the resulting seeds would only breed true if they are not cross pollinated with another variety of the same species. For example, tomoatos need to be pollinated with pollen from the same variety for the seeds in the resulting tomatos to be the same plant as the mother. If the flowers are pollinated with pollen from another variety, then the resulting tomatoes would include seeds with a mix of genes from both tomato plants.

Example:

Rutgers Tomato pollinated by Rutgers Tomato pollen = resulting seeds = Rutgers Tomato
Rutgers Tomato Pollinated by Husky Cherry = resulting seeds = Husky Rutgers (ie: a hybrid, the resulting seeds can produce plants with traits from both parents)

It is like dog breeding. Mate 2 poodles get a poodle. Mate a poodle and cocker spaniel, get a cockapoo.

That is why they say if you want to save seeds of open pollinated plants, you need to keep them separated from other varieties.

Now, there are self pollinating varieties where each flower will pollinate itself, greatly reducing the chance of cross pollination.

Here is a link with more info: Pollination Link

Pete

Good link, GS. If you really want to grow open pollinated and have them breed true to form, then grow only one variety, and check to make sure close neighbours aren't growing that plant. Corn, for example, needs to be planted 600' from other varieties to breed true. Tomatoes at about 10', and beans 4-6'. I planted a purple cherokee in my ornamental garden which is 25' from the SFG so it would breed true. At the rear of the house is a black krim for the same reason. One planting of dragon's tongue beans for seed only is in the ornamental garden.

I haven't found a single website that provides recommended distances for pure pollination, but this one has some distances posted:

http://www.clemson.edu/extension/hgic/plants/vegetables/gardening/hgic1255.html

Belfrybat...great info.
Thank you.

I have been reading the book "The New Seed Starters Handbook". It is a great 300+ page resource on starting seeds. It also has several sections on saving seeds. I know she gives distances from plants but I haven't gotten to that section yet. She also talks about wind pollination and suggests covering strains of cross-pollinating species with cheese-cloth covered cages. The plants have to be hand pollinated but the cheese-cloth keeps the bees from pollinating across varieties.

Hybrid plants do not breed true so I wouldn't bother with all the work for those.

Good luck! Oh, and if you are interested in the book, there is a long preview of it on Amazon. Makes a nice "bedtime" read.