Skip to main content

Breeding Practices

Mass Segregation

Part 7

Now we are ready for the fun to begin! The F2 generation is where all the genetics start to segregate out into the different plant and fruit types as the dominant and recessive genes split up and pair off. This is the generation where there’s the widest variety of segregation happening, so it’s best to sow as many seeds as possible so you can see all the differences side by side in your garden and select for the best traits.
If the parents are fairly stable and you have one that was indeterminate and one that was a dwarf variety, there will be a roughly 25 percent chance of finding dwarf varieties in the F2 generation. This percentage can be greater or lesser, depending on the complexity of the genetics contained within each parent. For this reason, it is sometimes better to use parents that are both stable before making the cross so you can better predict the outcomes. Many crosses made with stable parents can be stabilized by the sixth through the ninth generation. If a cross is made with unstable parents, the segregates may be unstable for many generations, even up into the twenties!
This generation is another milestone where a breeder should take several photos of the F2 plants and fruit they have grown out, documenting any particular traits they notice along the way. These notes and photos will be used as a reference tool for subsequent generations. In the photos below, you will see some F2 siblings found this last summer in my garden; some were on dwarf plants, and some came to me on wispy indeterminate vines. The variety among fruit colors was phenomenal!

Reader Comments

No comments yet
About The Author
  • Chief Operating Officer, Director of Research and Innovation
Also in this series

Try it

Sign up for a free membership and set up your dashboard. Get a taste of our rich content and view up to 12 tomatoes, recipes, bugs, articles, and videos on us!