Crossability analysis in subgenus Tulipa of the genus Tulipa L.

Abstract

A range of almost 1400 cross combinations has been carried out between 31 species of Tulipa subgenus Tulipa. Most of the sections are well separated reproductively from each other. The designated species aggregates in section Clusianae appeared to be intersterile. Also in section Kolpakowskianae the species, as far as used, cannot be combined. Some crosses between species of section Tulipanum succeeded. The species of sections Eichleres and Tulipa (including the cultivated tulip T gesneriana) could be combined in various ways, although the highest level of seed set was achieved within either section. The crossability data support the current taxonomic division. The level of reproductive isolation between sympatric species is discussed, and the importance of crossability studies for plant breeding in Tulipa pointed out briefly.