Emel Sözen

A Preliminary Study on the Genetic Diversity of the Critically Endangered Centaures nivea (Asteraceae)

Centaurea nivea (Asteraceae) is endemic to Turkey and distributed only in the Eskişehir Province. It is under risk of extinction due to anthropogenic disturbance, so conservation strategies must be developed urgently. In this study, RAPD technique was used to estimate the level of genetic diversity of C. nivea. Twenty RAPD primers generated 234 bands, of which 215 were polymorphic (91.88%). A high level of genetic diversity was detected both at population (PPB = 72.90%, I = 0.3790, Hs = 0.2527) and at species level (PPB = 91.88%, I = 0.4510, Ht = 0.2963). A moderate level of genetic differentiation among populations was also revealed by Neis gene diversity analysis (14.73%), Shannons information measure (15.96%) and AMOVA (7.97%). Patterns of genetic variation among the populations of C. nivea may indicate that the closely located and fragmented populations of C. nivea were likely derived from a previously large population.

Isolation of quality total RNA from the aromatic plant Origanum onites.

We successfully used the guanidine isothiocyanate method for isolation of total RNA from leaf, stem, and root tissues of the aromatic plant Origanum onites. The RNA was extracted with TRI Reagent® at room temperature and was recovered by isopropanol precipitation. The isolated RNA was capable of reverse transcription. The extraction method described here does not require ultracentrifugation, and it is fast, simple, and effective. The procedure can be completed within 3 hours and may be applicable to other aromatic medicinal plants containing high amounts of phenolic compounds.

Rapid and high quality DNA isolation from Origanum onites for RAPD and ISSR analysis.

Origanum onites is an economically important medicinal plant with high essential oil content. Lack of an appropriate DNA isolation procedure is a limiting factor for any molecular study of this plant. We have used a protocol for genomic DNA isolation based on a hexadecyltrimethylammonium bromide (CTAB) method described for other plant species. The method involves mortar grinding of leaf tissue, modified CTAB extraction using high salt concentrations and polyvinyl pyrrolidone, and successive isoamyl alcohol/chloroform extractions. The yield was approx. 20 μg DNA per 200 mg of initial fresh plant material. The genomic DNA obtained by this method was suitable to be used in restriction digests, inter simple sequence repeat (ISSR) and randomly amplified polymorphic DNA (RAPD) reactions. This extraction method should facilitate the molecular analysis of Origanum chemotypes.