Ricotia L. (Brassicaceae) cinsinin filogeni ve filocoğrafyası

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Thesis Type: Doctorate

Institution Of The Thesis: Hacettepe Üniversitesi, Fen Bilimleri Enstitüsü, Biyoloji A.B.D., Turkey

Approval Date: 2015

Thesis Language: Turkish

Student: BARIŞ ÖZÜDOĞRU

Principal Supervisor (For Co-Supervisor Theses): GALİP AKAYDIN

Supervisor: SADIK ERİK

Open Archive Collection: AVESIS Open Access Collection

Abstract:

In this study, phylogeny and phylogeography of genus Ricotia L. (Brassicaceae), which is represented by nine species in eastern Mediterranean Region, is examined. Assigning Ricotia into a particular tribe, which has not been performed yet, determining outline of the genus limits, solving taxonomic problems and revealing biogeographic relationship of species is the aim of this study. In order to achieve these aims, morphological, molecular, cytometric and Ecological Niche Modelling (ENM) methods are performed. Study materials are mainly collected from Turkey and Greece. Apart from those, other samples are obtained from Israel Gene bank and various herbaria. Nuclear Internal Transcribed Spacer (ITS) and plastidic trnL-F, rps16-trnQ and rpL32-trnL (UAG) DNA regions are used to clarify both systematic position of genus in the family and infrageneric phylogeographic relationships. The results clearly indicate that Ricotia should be assigned into tribe Biscutelleae along with Lunaria, Biscutella and Megadenia. A new description and diagnostic key is generated for this united tribe. The inadequate descriptions are revised and a new diagnostig key is also generated for genus. Furthermore, distribution areas and IUCN categories of species are updated. Four Ricotia lineages described in phylogenetic studies were tested using seed shape analyses, but apart from "tenuifolia" lineage, the seed data was incompetent to distinguish lineages. Divergence time estimations, carried out by using both a secondary calibration approach and published ITS substitution rates, indicate that the origin of Ricotia (9.2-11.3 million years ago (mya)) predates the onset of the Mediterranean climate after the Messinian Salinity Crisis (5.9-5.3 mya). Ancestral Area Reconstruction analyses revealed with a 54.1% probability that Ricotia arose in the Anatolian Diagonal Region. Also, the results of the Ancestral Character State Reconstruction analyses, which are used for determining the origin of important taxonomical characters in Ricotia systematics showed that Ricotia is originated from a perennial ancestral species (with 93.5 % probability) with ovate/orbicular and indehiscent fruit (with 78.9 % probability) and also without replum (with 78.9 % probability). Finally, molecular phylogeography and Ecological Niche Modelling (ENM) analyses revealed that Ricotia species are in demographic equilibrium for ages (since mid Pleistocene (0.781-0.126 mya)).