Genetic Biodiversity of Italian Olives (Olea europaea) Germplasm Analyzed by SSR Markers

Abstract

The olive is an important fruit species cultivated for oil and table olives in Italy and the Mediterranean basin. The conservation of cultivated plants in ex situ collections is essential for the optimal management and use of their genetic resources. The largest ex situ olive germplasm collection consists of approximately 500 Italian olive varieties and corresponding to 85% of the total Italian olive germplasm is maintained at the Consiglio per la Ricerca e sperimentazione per l'Agricoltura, Centro di Ricerca per l'Olivicoltura e l'Industria Olearia (CRA-OLI), in Italy. In this work, eleven preselected nuclear microsatellite markers were used to assess genetic diversity, population structure, and gene flows with the aim of assembling a core collection. The dendrogram obtained utilizing the unweighted pair group method highlights the presence of homonymy and synonymy in olive tree datasets analyzed in this study. 439 different unique genotype profiles were obtained with this combination of 11 loci nSSR, representing 89.8% of the varieties analyzed. The remaining 10.2% comprises different variety pairs in which both accessions are genetically indistinguishable. Clustering analysis performed using BAPS software detected seven groups in Italian olive germplasm and gene flows were determined among identified clusters. We proposed an Italian core collection of 23 olive varieties capturing all detected alleles at microsatellites. The information collected in this study regarding the CRA-OLI ex situ collection can be used for breeding programs, for germplasm conservation, and for optimizing a strategy for the management of olive gene pools.

Genetic relationships in a germplasm collection of Camellia japonica and Camellia oleifera using SSR analysis

“…Microsatellite genotyping can allow unambiguous identification of germplasm (Dominguez-Garcia et al, 2012;Muzzalupo et al, 2014;Mousavi et al, 2014). Because of their high discriminatory power and typically straight forward interpretation (Taniguchi et al, 2014;Jia et al, 2015), SSR markers have been becoming the preferred choice for genetic identification of Camellia germplasm.…”

Genetic Diversity and Relationships among Local Olive (<i>Olea europeaea</i> L.) Genotypes from Gaziantep Province and Notable Cultivars in Turkey, Based on SSR Markers

“…Noormohammadi et al (2009) and Muzzalupo et al (2014) also found high polymorphism in olive cultivars with DCA9 marker.…”

“…The results indicate that the studied population may exhibit a high level of inbreeding within isolated and closely related individuals. Muzzalupo et al (2014) reported higher expected heterozygosity among 489 olive cultivars by using 11 nuclear SSR markers.…”

“…This enables clear identification of genetic polymorphism within and among olive cultivars. Previous research clearly indicated that the SSR technique was more appropriate than AFLPs and RAPDs for polymorphic detection, which more clearly distinguishes among closely related cultivars (Belaj et al, 2003;Montemurro et al, 2008;Muzzalupo et al, 2014;Abdessemed et al, 2015). In olive cultivar identification, microsatellites have a lot of advantages compared to the other PCR (Polymerase Chain Reaction) based molecular markers techniques due to co-dominant and easily reproducible characteristics, frequent and random distribution, thus allowing a wide coverage of the genome.…”

Direct DNA amplification from virgin olive oil for traceability and authenticity

“…Specifically, we studied and compared the genetic profiles for eleven SSR markers in VOO and olive cultivars. Moreover, in order to identify the variety of each sample, the SSR profiles of our samples were compared with the same SSR profiles included in the Certification of the varietal composition, geographic origin and the absence of synthetic products in the extra virgin olive oils (CERTOLIO) molecular database (http://www.certolio.org/data-base-molecolare/) [18], which presently holds molecular profiles of more than 500 olive cultivars.…”