Cytology in Silene: from population diversity to section classification

Abstract

Cytological studies were performed in 25 populations of six Silene species of the sections Inflatae Boiss., and Auriculatae Boiss., S. odontopetala Fenzi, S. vulgaris (Moench) Garcke, S. pungens Boiss., S. aucheriana Boiss., S. sisianica Boiss. & Buhse, and S. pseudaucheriana Melzh., showing 2n = 2x = 24 and 48. These are the first chromosome number reports for all six species. Among twelve populations of S. aucheriana, two populations had 2n=4x= 48 chromosome number, while the others had 2n=2x=24. ANOVA revealed significant chromosomal differences among S. aucheriana, S. odontopetala and S. vulgaris. ANOVA test also showed significant differences among sections, indicating the occurrence of significant quantitative changes in chromosome size during the species diversification. Meiotic analysis of S. odontopetala and S. aucheriana populations showed mainly bivalents and univalents in the metaphase of meiosis I, although some quadrivalents were observed too. Significant differences were formed for all meiotic characteristics among the sections studied, indicating a change in the number of genes controlling chromosome pairing and also heterozygote translocations as one of the adaptive strategies during the species diversification in Silene.