Early selection for forcing ability in tulip (Tulipa L.) breeding

Abstract

The long juvenile period and slow propagation of tulips are serious drawbacks in breeding. The Institute's programme is therefore aimed at the development of a method of early selection for forcing ability in seedling progenies.In earlier trials, comparing the behaviour of juvenile and adult bulbs of cultivars has yielded provisional criteria for pre-selection. These criteria have now been tested in some large progenies.It appeared that flowering date after forcing in the glasshouse -a measure for forcing ability -was correlated with both time of emergence and time of dying down during the juvenile phase.Pre-selection on these parameters can be carried out effectively during the second and third growth season in the field. At the end of the third season, the categories that are late for either character in both seasons may be discarded.