MORPHOLOGICAL, CYTOGENETIC AND MOLECULAR CHARACTERIZATION OF GYPSOPHILA SPECIES AND HYBRIDS

Gypsophila paniculata L. is one of the most economically important flower crops used for ornamental purposes in commercial cut-flower production (Moyal Ben Zvi et al. 2008, Barakat & El-Sammak, 2011) and represents an important target for the breeding of new varieties with novel improved traits. However, in this genus, classical genetic breeding is strongly hampered by the complete lack of the knowledge of its overall genetic structure. Molecular markers are quick and precise tools to identify genotypes in breeding programs that can increase our understanding on the origin of varieties, if unknown. Furthermore, in a breeding strategy, the characterization of chromosome number and the analysis of flower structure of parental genotypes are very important. To this aim, in this work the genetic characterization of a series of commercial hybrids and species of Gypsophila was determined using both AFLP as nuclear whole-genome markers and chloroplast simple sequence repeats (cpSSR) as applicable tools in cytoplasmic inheritance analysis. These markers were not used previously in this genus. Moreover, the determination of the chromosome numbers and the analysis of flower structure of parental genotypes were also carried out. Overall, data obtained with molecular markers have allowed us to divide the commercial hybrids into different sub-groups and to determine a probable relationship with the species of origin. Coherently with these results, significant differences in chromosome numbers among species and hybrids were also found. In addition, the flower structure and reproduction systems of commercial hybrids appeared remarkable complex. These results may help to accelerate the breeding process, leading to the development of varieties with new improved traits for quality and external characteristics, both significant for competitive products.