Assessment of genetic diversity of Zataria multiflora ecotypes by RAPD and ISSR

Assessment of genetic diversity and germplasm classification of plant species are important activities in plant improvement and management of genetic resources. Regarding observed variation on various traits of Zataria multiflora Bosis. random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers were used to assess genetic diversity of the species in Iran. Leaves were collected on thyme plants of 15 different regions of Kerman,
Sistan and Balochistan, Boushehr, Fars, and Khuzestan provinces. Leaf DNA extraction was carried out by cetyltrimethyl ammonium bromide (CTAB) method with small modifications. Ten RAPD markers and 10 ISSR markers with sharper bands in polymerase chain reaction (PCR) were used for data analysis. NTSYS-pc software and dice similarity coefficient, as well as Unweighted Pair Group Method with Arithmetic Averages (UPGMA) were used to draw the related dendrogram. Cophenetic correlation coefficient was calculated and a two-dimensional graph was created based on principle component analysis (PCA) results. Range of the bands produced by the primers varied from 120 to 3100bp. The 15 selected regions were classified into three separate groups. The established clusters were in a good harmony with geographical conditions. Entirely the markers produced 207 bands with polymorphism percentage of 86.9. The results of the dice similarity coefficient produced by NTYSIS suggested that genetic similarity of thyme varied between 0.4390–0.8460. The most genetic similarity was observed between Andimeshk and Eizeh samples and the least similarity was observed between Iranshahr and Jiroft samples. Results of principle components analysis and cluster analysis were similar. Cophenetic correlation coefficient was 74.60%. The results suggested that RAPD & ISSR markers are useful for investigating genetic variability of Zatraia multiflora germplasm.