Quick question: what 'F1' (for example 'Oceano F1' tomato seed) in name of seed exactly means? Are there other designations/markings in use, what is their meaning? Are there other naming conventions (for vegetable, fruit, flowers etc) and how important they are when choosing varieties?

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    In some parts of the world F1 seeds and plants, especially for fruits/vegetables are seen very critically. Patents, supplier-lock-ins, monopolies, biodiversity-doubts, old-varieties disappearance - just to name some of the controversial topics. For myself, I never use them and try to get local seeds by trading with locals - turns out, these plants work much better for me.
    – Patrick B.
    Commented May 28, 2019 at 8:34

2 Answers 2


F1 is a term from genetics, it means the first generation from a hybrid. Usually two inbred lines are crossed to get a hybrid, the new hybrid has specific characteristics (usually the best of both parents). If you cross F1 x F1 (so next generation, hence F2), there are chances you don't get exactly the same F1 tomato back (75% chance that a dominant trait reoccurs, and 25% chance for recessive ones). So if you want the same variety of tomatoes next year, don't use seeds produced by these F1 tomatoes, but buy new F1 seeds again.

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    Does it mean 'F2' seeds exist (possible to buy) or they become totaly new variety? Commented May 27, 2019 at 7:56
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    F2 exists in genetics, but for seeds it is not useful, since you don't know exactly what characteristics are in these F2 plants. For F1 you know that all plants are the same, for F2 not.
    – benn
    Commented May 27, 2019 at 7:59

The accepted answer already explains the meaning of F1 in gardening and seed production. However, it differs slightly from the original meaning in genetics, and also it doesn't explain what the "F" in F1 means; Thus, as a genetics teacher, I'd like to explain it a little further.

As it is well known, Mendel stablished the foundations of modern genetics. In his 1865 paper, Mendel uses the terms "parent plant", "first generation", "second generation" etc...

However, most of the terms used in genetics (including the very word "genetics") were coined by Bateson at the beginning of the 20th century, among them the term F1. And here's it's meaning:

The F in F1 means "filial", that is, "offspring".

The same way you can have F2, F3, F4 etc. Until today those terms (together with P for parental generation) are used in genetics diagrams, like this:

enter image description here

It's worth mentioning that, in genetics, F1 does not mean a hybrid generation. If the P generation is composed by two identical homozygous plants, for instance AA x AA, the offspring, despite not being hybrid, will still be called F1. Therefore in genetics F1 means just that, the first generation (filial one).

  • I always learned at school that "F" stood for the Latin word filius (son). Obviously "filial" is derived from that word.
    – benn
    Commented May 28, 2019 at 13:16
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    @benn yes, that's what a lot of people think. However, if you look at 1909 Bateson's book, you'll see "filial", in English: imgur.com/a/zW3C7C0 Commented May 28, 2019 at 14:03

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