Cytogenomic Differentiation of Narcissus serotinus s.l. in Southwestern Turkey: Insights into Polyploidy and Hybridization

The Narcissus serotinus complex is one of the most taxonomy-challenging groups within the genus Narcissus (Amaryllidaceae). While western Mediterranean populations have been studied thoroughly, eastern Mediterranean populations remain poorly understood. This taxonomic uncertainty has led to confusion about species boundaries, especially regarding the identity and distribution of cytotypes such as N. serotinus, N. obsoletus, and N. miniatus. This study aimed to clarify the taxonomic status and cytogenetic diversity of N. serotinus s.l. populations in southwestern and southern Turkey using an integrative approach. Morphological assessments, karyological analyses, and nuclear DNA content measurements were conducted on eight natural populations in detail. The analyses showed that all studied populations had a consistent chromosome number of 2n = 30, a cytotype not previously documented in the region. Nuclear DNA content ranged from 48.65 to 54.85 pg, indicating genomic variation despite uniform ploidy. Phenetic clustering based on combined morphological and cytogenetic data confirmed the existence of three main lineages, supporting the distinctiveness of N. miniatus and revealing previously unrecognized diversity within Turkish populations. The discovery of 2n = 30 cytotypes in Turkey expands the known cytogenetic and biogeographic range of the N. serotinus complex and supports recognizing N. miniatus as a distinct species. Additionally, this study emphasizes the importance of integrative taxonomy—combining morphological, cytogenetic, and genomic methods—in resolving complex plant groups. It also highlights the eastern Mediterranean, especially Turkey, as a key region for studying speciation, hybridization, and plant evolution within the genus Narcissus.