مطالعه روابط فيلوژنتيكي مولكولي و تخمين اندازه ژنوم در گونه‌هاي جنس Tilia L. (Malvaceae) در ايران

Study of Molecular Phylogenetic relationships an‎d estimation of Genome Size in species of the genus Tilia L. (Malvaceae) in Iran.

زيست شناسي گياهي و جانوري

The genus Tilia is one of the characteristic elements of the Hyrcanian forest vegetation in northern Iran, yet previous reports have offered differing accounts of its species composition. In this study, to investigate the phylogenetic relationships, population structure, an‎d ploidy level of Iranian limes, a set of samples from the Hyrcanian forests, together with several European accessions, was examined. Two complementary approaches were employed: Genotyping-by-Sequencing (GBS) to generate thousan‎ds of SNP markers an‎d infer phylogenetic relationships, an‎d genome size estimation to determine ploidy levels. The GBS dataset enabled the reconstruction of phylogenetic trees using ML an‎d MP methods, network analyses, an‎d assessments of population structure via PCA an‎d ancestry models. The results showed that the Iranian samples collected in this study form a relatively cohesive genetic group, most closely aligned with Tilia dasystyla subsp. caucasica. Genome size analyses further indicated a consistent tetraploid pattern across all Iranian samples, whereas the European specimens were predominantly diploid. Within the Hyrcanian material, a subset of trees with spoon-shaped bracts, morphologically similar to T. sabetii, was identified an‎d could be distinguished based on morphology. Integrating GBS data with genome size information provided a unified perspective on the phylogenetic relationships an‎d diversity patterns in the Hyrcanian limes, revealing that most observed differences occur at the population level rather than at the species level. These findings provide a basis for a more refined taxonomic reassessment of Tilia in Iran an‎d for conservation planning informed by genetic evidence in the Hyrcanian forests.

4

154425