Analysis of Sardinian myrtle (Myrtus communis L.) germplasm selections by SSR markers

Myrtus communis L., an evergreen shrub of the Mediterranean maquis, is widely used for its medicinal and aromatic properties due to the essential oil content of its leaves and fruits. It is also used as an ornamental plant and as a cut foliage crop. In Sardinia, myrtle leaves and berries are used for the production of traditional myrtle liqueurs. In this study, we report the use of simple sequence repeats (SSR) markers to assess the genetic diversity among some Sardinian myrtle cultivars grown at the “Antonio Milella" Experimental Station located in Oristano (Sardinia, Italy). Forty cultivars were sampled from this collection, resulting from a morphology-based selection program initiated in 1995. Genomic DNA was extracted from young leaves using a commercial kit, and used as template for PCR analysis with a set of 14 primer pairs. Fluorescently labeled amplification products were run on a capillary sequencer. Genetic structure was investigated using the Bayesian clustering model implemented in the STRUCTURE 2.3.3 software. The SSR markers used in this study identified genetic variability among the studied myrtle cultivars and can be helpful in the selection of material for obtaining new commercial cultivars and for implementing myrtle preservation programs.