Interspecific crosses between Tulipa gesneriana cultivars and wild Tulipa species: a survey

Summary

Interspecific crosses were made between 76 Tulipa gesneriana cultivars and 28 botanical Tulipa species. Tulipa gesneriana proved fully congruent (all cross-combinations giving hybrid progeny) with members of the subsection Gesnerianae, was moderately affiliated (50% of all cross-combinations giving hybrid progeny) with representatives of the subsection Eichleres, and was found to be incongruent with most other Tulipa species (except T. stapfii of the subsection Oculussolis).

Relationships between T. gesneriana and some representatives of the subsection Eichleres were addressed in more detail. Seeds were harvested in all cross-combinations, but the number of seeds depended on the T. gesneriana cultivar used as the female partner. Apparently, the maternal genotype did affect pre- or post-fertilization processes.

T. gesneriana was not crossable with T. kaufmanniana of the subsection Spiranthera. In this specific case, however, a bridge cross was used to overcome incongruity. For this, T. kaufmanniana was first combined with T. greigii, and the hybrid was subsequently crossed with T. gesneriana.

These results demonstrate possibilities for interspecific cross-combinations in tulips and have offered opportunities for the introduction of desired new traits in the cultivated tulip.