Biogeography of Rhaponticoides, an Irano-Turanian element in the Mediterranean flora.

Floristic relationships between the Irano-Turanian and Mediterranean regions have been known from old. However, only a few biogeographical analyses based on molecular data have evaluated the history of steppe plants within the Mediterranean basin. Our study aims to contribute to a better understanding of the migratory and diversification processes by reconstructing the biogeography of Rhaponticoides (Cardueae), distributed in the Mediterranean and Irano-Turanian regions. We generated nuclear and plastid sequences that were analyzed by Bayesian inference. We used the resulting phylogeny for dating the diversification of the genus and examining the dispersal pathways. Two clades were recovered, an Irano-Turanian clade and a Mediterranean clade. The origin of the genus was placed in the Anatolian plateau in the Middle Miocene. The genus experienced several diversifications and expansions correlated to the Messinian salinity crisis and the environmental changes in the Pliocene and the Quaternary. Rhaponticoides migrated following two routes reflecting the two souls of the genus: Irano-Turanian taxa colonized the steppes of Eurasia whilst Mediterranean species migrated via eastern and central Mediterranean and North Africa, leaving a trail of species; both pathways ended in the Iberian Peninsula. Our study also confirms that more work is needed to unravel phylogenetic relationships in Rhaponticoides.

The comparative palynomorphological studies on Turkish Muscari genera and close relatives (Asparagaceae-scilloideae) with their taxonomic implications.

By this study, the palynomorphological traits of 49 taxa (53 plant samples) of the genus Muscari which has been the main research topic and also its relatives, Pseudomuscari, Hyacinthella and Bellevalia have been studied in details of both using light and scanning electron microscope. In the end of palynologic works, it was suggested the descriptive or symbolized main pollen types to make easier the separation or identification of the species of Muscari and its relative groups. According to this symbolization, the pollen types of species may be changeable as D-shaped, elliptical, triangular, and spindle shaped and all types could be seen in different members of the studied taxonomic groups in this paper. One of the most important findings of the study is that the taxa of the genus Muscari, Hyacinthella and Bellevalia do not show a main difference in terms of pollen structures and especially they exhibit harmony. Therefore, it does not possible to mention about the special pollen shape own to one species but it is possible to see common pollen types for closely related taxa or taxon groups. As a result, it could be commented that there is not evolved the close taxonomical groups within Asparagaceae in terms of pollen shape and morphologies and there is considerably a high suitability in point of theirs germ cells or microspores among them. RESEARCH HIGHLIGHTS: A detailed palynological description is provided for Muscari and close relative genus using scanning electron microscopy (SEM) and light microscopy (LM). Pollen size and sulcus length are been determined as the best informative pollen characters to understand Muscari and other studied species.