Temperature Effects on Interspecific Hybridization between Gladiolus ×grandiflora and G. tristis

Abstract

Interspecific hybridization between a modern cultivar of Gladiolu×grandiflora hort. (2n = 60) and the wild species G. tristis L. (2n = 30) was made to introduce characteristics of the wild species into the cultivated one. Gladiolus ×grandiflora is a summer-flowering species, and G. tristis flowers in winter. The effect of storage temperature on pollen viability was tested, as long-term storage of pollen was necessary to facilitate crossing these two species. Pollen of G. tristis could be stored at -20 °C for ≈1 year, and was more practical than storage at -80 °C. Air temperature affected pollen tube growth, fertility, and fruit set in the cross between G. ×grandiflora and G. tristis, and low temperatures (15 to 20 °C) were best. The morphological data and flow cytometric analysis showed that the F1 plants were hybrids between G. ×grandiflora and G. tristis.