What Does F1 After A Variety Name Mean?

I notice that several of the new All-America vegetable winners have an “F1” suffix attached. Could you explain what it means.

“F1” is a label that designates a plant variety as a first generation hybrid. Hybrid varieties have been developed from a multiple generation plant breeding process used by plant breeders to produce new varieties with exceptional vigor and uniformity.

Plant breeders (sometimes referred to as “hybridizers”) begin by selecting plants with desirable qualities from a wide range of sources. Individual plants are self-pollinated and the resulting seeds are grown and a few of the best are again selected for self-pollination. After about 3 or 4 generations of selection all of the plants from a single selection become quite uniform because all of their genes are the same.

Individual selections from different sources are then hand cross-pollinated to produce hybrids (often referred to as test crosses). Typically dozens of these test crosses are grown and compared in variety trials. A few of the best are chosen to be named as new varieties and commercial seed production is begun.

The resulting new F1 varieties are extremely uniform (every plant is identical) because they get a uniform set of genes from both parents. They also have extra vigor because of the wide diversity of genes from 2 different parents.

If seed is saved from these F1 hybrid plants it is very non-uniform because the diversity of genes are recombined in numerous ways.

Some people consider F1 hybrids as unnatural because they are being controlled by man. However, these same processes occur in nature. Some plants are self-pollinated and others are cross-pollinated. Those natural hybrids from cross-pollination stand out with extra vigor and are sometimes selected by man.

I recommend growing F1 varieties because of their superior vigor and uniformity. However, I do not recommend saving seed from them because they do not grow true to type.



Allen Wilson

Allen has been writing about gardening for over 30 years. He is a retired professor of Horticulture.

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