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Used for convenience to denote the first filial generation, or the hybrids arising from a first cross, successive generations arising from this one being denoted by F2, F3, etc. P1 denotes the parents of the F1 generation, P2 the grandparents, and so on.

denotes first filial generation, or hybrids arising from a first cross, successive generations arising from this one being denoted by F2, F3, etc. P1 denotes parents of F1 generation, P2 the grandparents, etc.