Genetic Evidence of Intra-cultivar Variability within Iberian Olive Cultivars

Abstract

<jats:p>A collection of 130 olive samples, originating from diverse areas in Europe and corresponding to 67 different cultivars denominations, was genotyped at 14 microsatellite loci. In total, 135 alleles with a mean number of 9.6 alleles per locus were detected. All but 30 accessions showed unique genotypes. Several cases of synonymy listed in the FAO database of olive germplasm could not be confirmed, as different allelic profiles were obtained from putatively synonymous cultivars. The existence of homonyms or mislabeled samples in olive germplasm collections was evidenced by allele differences of up to 60% between samples of the same denomination. An allele-sharing phenogram of the analyzed genotypes revealed several cultivars with high levels of intra-varietal polymorphism, as well as cultivar families consisting of closely related cultivars with similar denominations. Our work shows that the current designations of olive cultivars fall short of describing the genetic variability among economically important plant material. A thorough investigation of the existing variability will prove of major importance for both management and economic production of olive trees.</jats:p>

Genetic diversity assessment in Portugal accessions of Olea europaea by RAPD markers

“…In the present study, the different position of the cv. Galega in comparison to the other 28 cultivars, similar to that reported by other authors (Gemas et al 2004, Lopes et al 2004, suggest that it has a different origin. Moreover, Belaj et al (2002), studying 6 of these 29 Portuguese cultivars, found the same grouping among them as in the present work, and Galega also was independent.…”

SSR Marker-Based DNA Fingerprinting and Cultivar Identification of Olives (Olea europaea)

“…SSR markers have been previously used in genetic diversity and relationship studies in olive cultivars, and most scientists conclude that SSR markers are a powerful tool for cultivar identification and analysis of genetic structure (Khadari et al 2003;Belaj et al 2003;Gomes et al 2009). Variations reported in the number of alleles in olive cultivars by different scientists may be related to variation in the loci studied as well as the number of genotypes and their localities (Lopes et al 2004) The dendrogram derived from UPGMA cluster analysis of the 32 SSR markers showed two main, distinct groups (Fig. 1).…”

Development of a large set of SNP markers for assessing phylogenetic relationships between the olive cultivars composing the Israeli olive germplasm collection

“…At most, we have found a variant genotype at 2 SNP loci between trees of the same cultivar. The rate of intra-cultivar mutation calculated from microsatellites was much higher, ranging from a rate of 2 out of 30 loci in one study (Cipriani et al 2002) up to 15 % of the analyzed alleles in a second study (Lopes et al 2004). The SNP marker mutation rate is considerably lower than that of microsatellites (Kronholm et al 2010).…”