Traditional maintenance breeding of landraces: 2. Practical and theoretical considerations on maintenance of variation of landraces by farmers and gardeners

摘要

Maintenance breeding of landraces is discussed. Various practical andtheoretical advices, presented in the literature to collectors of genebankshave been used to compare these with the methods applied by farmers.Although most farmers realize the utmost importance of yield stability, theyand their ancestors experienced that maintenance breeding could better bereplaced by seed replacement. A few crops such as rootstock rose andespecially maize, form exceptions. In these crops the farmers actually collect`hips', or ears for the next generation. However, they also apply seedreplacement from time to time.More research is needed to obtain better knowledge about the level ofvariation of a landrace grown for various generations before and after seedreplacement.