Simple Sequence Repeat Identification and Endocarp Characterization of Olive Tree Accessions in a Tunisian Germplasm Collection

Abstract

<jats:p>Most traditional olive-producing countries possess a diversified genetic patrimony in <jats:italic>Olea europaea</jats:italic> L. Since the emergence of modern olive growing system, the identification, classification, and conservation of autochthonous olive cultivars is a priority for these countries. In this work, a total of 84 accessions belonging to the “Boughrara”-Sfax olive germplasm collection located in Tunisia have been screened using a powerful set of eight simple sequence repeat markers (SSRs). The study revealed a high genetic variability among the collection and detected a total of 64 alleles. For better management of the mentioned germplasm bank, an improved classification of the entries, including new denominations, has been proposed. In addition, several cases of mislabeling, synonymy, and homonymy have been clarified. Genetic relationships among cultivars have been analyzed showing four major clusters. Finally, a correspondence factor analysis demonstrated that cultivars tend to cluster depending on their main use as oil or table olives. No clear clustering tendencies were observed when the geographical origin of cultivars was used as the criteria for the analysis. All results obtained by SSR screening and classification were in accordance with classification based on morphological traits of fruit endocarps.</jats:p>

Evaluation of some Productive and Technological Traits in Local and Introduced Olive Cultivars (Olea europaea L.)

“…It's known that stone characters are not affected by environmental conditions [16], and this is proved in our results. No difference was detected between the average of stone weight between the two years and for all studied cultivars.…”

“…(Figure 3). It's obvious that the pulp/fruit ratio is affected by fruit weight more than stone weight, because stone weight is more stable and not affected by environmental conditions and agricultural practices as fruit weights [16]. (Table 3) High oil content (Frantoio and Khdairi), medium oil content (Coratina, Tanche, Chemlaly, Picholine, and Dermlali), and low oil content (Trilia, Zorzalina, Konservolia, Chemlal, and Gordal).…”

Description of olive morphological parameters by using open access software

“…Traditionally, these characteristics have been widely used for descriptive purposes to distinguish olive cultivars [3, 14–18]. Several descriptors which are related to leaf, fruit and endocarp traits have been shown to be mostly genetically determined with limited influence by the environment [19, 20]. Morphological characteristics are sometimes correlated or associated with disease susceptibility and can be used as markers in breeding for disease tolerance [21–23].…”

Characterization and Identification of Indigenous Olive Germplasm from Cyprus Using Morphological and Simple Sequence Repeat Markers

“…Traits related to the endocarp stand out for their major discriminative capacity, limited fluctuation, and ease of conservation (Barranco et al, 2005;Trujillo et al, 2006). For these reasons, the description of the endocarp frequently has been used to catalogue olive cultivars (Barranco et al, 2000(Barranco et al, , 2005Fendri et al, 2010;D'Imperio et al, 2011) and large collections of olive germplasm (Trujillo et al, 2014).…”

“…The polymerase chain reaction (PCR)-SSR technique has been used widely in olive varietal characterization, as it consists of a relatively simple methodology that permits an easy interpretation of results (Fendri et al, 2010;Rafalski and Tingey, 1993). Actually, the microsatellite markers (SSRs) are considered as leading markers for conducting varietal characterization and identification studies on olive (Anestiadou et al, 2017; Baldoni et al, 2009;Carriero et al, 2002;Cipriani et al, 2002;De La Rosa et al, 2002;Díez et al, 2011Díez et al, , 2012D'Imperio et al, 2011;Fendri et al, 2010;Haouane et al, 2011;Rallo et al, 2000;Sefc et al, 2000;Trujillo et al, 2014). Their discriminative capacity, consistency, codominant nature, easy interpretation, and low cost account for their success.…”