Morphological and cytological observations of wild species and hybrids of Gypsophila

Gypsophila paniculata L. is among the 10 best selling cut flower species globally and is considered a "target" plant for breeding varieties. The aim of this work was to make the genetic improvement of Gypsophila more rational and focused. The study of basic chromosome number and the reproductive system (potential barriers to intraspecific and interspecific incompatibilities) of the wild species as well as the commercial hybrids forms the basis of crossbreeding and selection of variety. A significant difference in ploidy was found between the species paniculata, its cultivar Flocon de Neige doubles, the species libanotica Boiss. (n = 34) and Pacifica Kom. (n = 68). A significant difference in the chromosome number was found among the commercial hybrids of Gypsophila under investigation, and this difference was observed among them as well as when compared with the wild type species. The flower structure of commercial hybrids can be remarkably complex. Some hybrids such as Biancanieves® and MeryG® showed empty pollen sacs, whereas others such as "Mirabella" and New Love® showed pollen grains trapped into anthers. However, the pollen, when present, exhibits immature or degenerated appearance. The examined commercial hybrids showed a gynoecium morphologically and anatomically conforming to that of wild species and it was potentially fertile. Therefore, the fertile pollen collected from the wild species could be used to fertilize the compatible eggs of commercial hybrids, thereby speeding the process of breeding varieties