The olive is a fruit tree species with a century-old history of cultivation in theMediterranean basin. In Apulia (Southern Italy), the olive is of main social, cultural and economicimportance, and represents a hallmark of the rural landscape. However, olive cultivation in thisregion is threatened by the recent spread of the olive quick decline syndrome (OQDS) disease, thusthere is an urgent need to explore biodiversity and search for genetic sources of resistance. Herein,a genetic variation in Apulian olive germplasm was explored, as a first step to identify genotypeswith enhanced bio-agronomic traits, including resistance to OQDS. A preselected set of nuclearmicrosatellite markers allowed the acquisition of genotypic profiles, and to define geneticrelationships between Apulian germplasm and widespread cultivars. The analysis highlighted thebroad genetic variation in Apulian accessions and the presence of different unique genetic profiles.The results of this study lay a foundation for the organization of new breeding programs for olivegenetic improvement.

Olive is one of the oldest cultivated species in the Mediterranean Basin, including Tunisia, where it has a wide diversity, with more than 200 cultivars, of both wild and feral forms. Many minor cultivars are still present in marginal areas of Tunisia, where they are maintained by farmers in small local groves, but they are poorly characterized and evaluated. In order to recover this neglected germplasm, surveys were conducted in different areas, and 31 genotypes were collected, molecularly characterized with 12 nuclear microsatellite (simple sequence repeat (SSR)) markers, and compared with 26 reference cultivars present in the Tunisian National Olive collection. The analysis revealed an overall high genetic diversity of this olive’s germplasm, but also discovered the presence of synonymies and homonymies among the commercialized varieties. The structure analysis showed the presence of different gene pools in the analyzed germplasm. In particular, the marginal germplasm from Ras Jbal and Azmour is characterized by gene pools not present in commercial (Nurseries) varieties, pointing out the very narrow genetic base of the commercialized olive material in Tunisia, and the need to broaden it to avoid the risk of genetic erosion of this species in this country.

Among the countries of the Mediterranean Basin, Tunisia is located at the crossroad for the immigration of several civilizations over the last two millennia, becoming a strategic place for gene flow, and a secondary center of diversity for olive species. Olive is one of the principal crop species in Tunisia and now it strongly characterizes the rural landscape of the country. In recent years, collecting missions on farm and in situ were carried out by various institutes, with special emphasis given to ex situ collections serving as a reference for the identification of olive germplasm. Simple Sequence Repeats (SSRs) represent the easiest and cheapest markers for olive genetic fingerprinting and have been the tool of choice for studying the genetic diversity of this crop in Tunisia, to resolve cases of homonymy and synonymy among the commercialized varieties, to identify rare cultivars, to improve knowledge about the genetic variability of this crop, to identify a hot spot of olive biodiversity in the Tunisian oasis of Degache, and to enrich the national reference collection of olive varieties. The present review describes the state of the art of the genetic characterization of the Tunisian olive germplasm and illustrate the progress obtained through the SSR markers, in individuating interesting genotypes that could be used for facing incoming problems determined by climate changes.

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The present study was conducted to understand the genetic diversity of bread wheat's that grown in Algeria, and to evaluate polymorphism information content (PIC) of some wheat SSR primers. It was undertaken to examine the genetic diversity of ten bread wheat (Triticum aestivum L.) genotypes, using 16 microsatellite primer pairs (SSRs). SSR bands were scored across all genotypes, for presence (1) or absence (0) and transformed into 0/1 binary matrix. A pair-wise similarity matrix was generated with the software NTSYS. The Polymorphism Information Content (PIC) ranged from 0.23 to 0.70 respectively for the primer WMC 21 and WMC 50 with an average of 0.49 and 0.52 per primer pair. The similarity coefficient between cultivars ranged from 0.28 and 0.91 with an average of 0.60. Most of the genotypes showed a high degree of genetic similarity. The highest genetic distance value of 0.91 has been scored between Kauz/Pastor/Fiscal and Prl/2*Pastor and between Kauz/Pastor/Fiscal and Wbll1*2/Brambling. The lowest genetic distance value of 0.28 has been scored between Arz and Babax/Lr42//Babax*2/3/Kukuna. Cluster analysis based on microsatellite allelic diversity discriminated the varieties into different clusters. Ten wheat cultivars were grouped in three clusters. The present study also indicates that microsatellite markers permit the fast and high throughout fingerprinting of accessions from a varieties collection in order to assess genetic diversity.

The study of the morphological characters of olive fruit and endocarp was carried out for 48 varieties planted in the collection of Boughrara (Sfax, Tunisia) and was compared to their characterization in the Tunisian catalog in their centers of origin. The study interested 8 characters for the fruit and 7 characters for the endocarp. The similarity rate was 73.3% for fruit characters and 64.6% for endocarp characters and eight characters of the two organs had similarity rates greater than 70%, particularly the weight, the apex shape and the presence of the nipple. Most varieties had similar identification for a total number of characters between 8 to 14 characters. The data revealed that the fruit contributed with 5 to 6 characters in the similarity of the varieties in the two databases against 4 to 5 characters for the endocarp. The results obtained showed a relatively strong discriminating power of the morphological characters in the identification of the different olive varieties in-situ and ex-situ conditions with an advantage for the fruit characters. Contribution/Originality:In the present work, we used morphological characterization in situ conditions compared to in-situ conditions for 48 olive varieties. The comparison of endocarp and fruit characters allowed to see how much is the importance of these characters in the characterization of varieties in different environments.

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