The genetic diversity of Sardinian myrtle (Myrtus communis L.) populations

Abstract

Background:The myrtle (Myrtus communis) is a common shrub widespread in the Mediterranean Basin. Its fruit and leaves exhibit antioxidant, antibacterial and antifungal properties, and are used for their content of essential oils and for their medicinal properties, but most commonly as an ingredient in locally made liquor. The uncontrolled exploitation of natural stands has reduced both the species' geographical coverage and the size of individual populations. The selection of genotypes for controlled cultivation requires a characterization of the genetic diversity present both within and between populations. Results: Genotypic variation was evaluated using ISSR profiling and genetic diversity characterized using standard population genetics approaches. Two major clusters were identified: one capturing all the candidate cultivars selected from various Sardinian localities, and the other wild individuals collected from Asinara, Corsica and Surigheddu. A moderate level of gene flow between the Sardinian and Corsican populations was identified. Discriminant analysis of principal components revealed a level of separation among the wild populations, confirming the population structure identified by the clustering methods. Conclusions: The wild accessions were well differentiated from the candidate cultivars. The level of genetic variability was high. The genetic data were compatible with the notion that myrtle has a mixed pollination system, including both out-pollination by insects and self-pollination. The candidate cultivars are suggested to represent an appropriate basis for directed breeding.

Morphological, chemical, and genetic diversity of wild myrtle(Myrtus communis L.) populations in Sicily

“…Only in recent times has the genetic variability of wild and candidate cultivar selections in Sardinia been deeply explored (Melito et al, 2013a(Melito et al, , 2014. This genetic approach highlighted the importance of the molecular markers in assessing the genetic diversity in wild accession and candidate cultivar selections.…”

Genetic diversity and population structure of wild Sardinian Myrtle (Myrtus communis L.) genotypes from different microclimatic areas

“…Previous studies on Italian (Melito et al, 2016;Agrimonti et al, 2007;Melito et al, 2013a;Melito et al, 2014) and Mediterranean myrtle populations (Bruna et al, 2007;Nora et al, 2015;Messaud et al, 2011;Serce et al, 2008;Albaladejo et al, 2009) showed that dominant and codominant molecular markers could associate genotype to a specific geographic area. In particular, AFLPs are extremely useful to assess the genetic diversity of myrtle, screening a large number of loci simultaneously without any preliminary knowledge on the genotype sequence.…”

“…Several studies conducted on Italian myrtle populations have shown that molecular markers can be successfully used to characterize natural populations (Agrimonti et al, 2007;Bruna et al, 2007;Melito et al, 2013a;Melito et al, 2016). More recently, AFLP analysis has been performed to characterize domesticated (Melito et al, 2014) and wild myrtle populations (Melito et al, 2016), respectively, in Sardinia and Sicily.…”

“…As a consequence, a conservation program is required to supply the liquor and pharmaceutical industries plant material request and to preserve and contain the reduction of natural population's diffusion (Melito et al, 2013a;Mulas and Melis, 2011). The preservation of myrtle population's natural diversity represents a long term strategy for domestication and future cultivars selection.…”

“…Particularly in Sardinia land, this strategy could evolve in the selection of cultivars with adaptability to growing conditions (Melito et al, 2013a).…”