Studio dell'influenza delle variabili agrometeorologiche sulla diversità genetica in Myrtus communis

Myrtus communis L.is an evergreen shrub of the Mediterranean maquis. This work reported the use of Simple Sequence Repeats (SSR) markers (14 primers pair) to assess the genetic diversity within some Sardinian population and the correlation of this diversity with some environmental and climate characteristics. I defined the genetic profiles of 22 population divided in 400 wild accessions and 65 candidate cultivar. SSR analysis attested an high polymorphism level (93% of the loci analyzed).Structure analysis divided the myrtle population into two main genetic groups (K=2). The analysis of the genetic diversity distribution in the populations examined, displayed a geographical gradient from north to south, which reflects the Sardinian shape, and from west to east, which reflects the Sardinian mountain distribution. The partial Mantel test found a positive correlation between mean temperature and genetic distance, but none between minimum and maximum temperature and mean precipitation.In conclusion, the wild accessions were well differentiated than candidate cultivars. The level of genetic variability was high. The genetic data confirmed that myrtle has a mixed pollination system, including both out-pollination by insects and self-pollination.This work represents the first attempt to characterize the myrtle Sardinian germplasm from a genetic and environmental point of view.