Transposon activation is a major driver in the genome evolution of cultivated olive trees (Olea europaea L.)

Abstract

The primary domestication of olive (Olea europaea L.) in the Levant dates back to the Neolithic period, around 6,000-5,500 BC, as some archeological remains attest.Cultivated olive trees are reproduced clonally, with sexual crosses being the sporadic events that drive the development of new varieties. In order to determine the genomic changes which have occurred in a modern olive cultivar, the genome of the Picual cultivar, one of the most popular olive varieties, was sequenced. Additional 40 cultivated and 10 wild accessions were re-sequenced to elucidate the evolution of the olive genome during the domestication process. It was found that the genome of the 'Picual' cultivar contains 79,667 gene models, of which 78,079 were protein-coding genes and 1,588 were tRNA. Population analyses support two independent events in olive domestication, including an early possible genetic bottleneck. Despite genetic

Genome Wild Analysis and Molecular Understanding of the Aquaporin Diversity in Olive Trees (Olea Europaea L.)

“…The OleurAQP superfamily expansion is linked to the fact that the Olea genome was subjected to two rounds of tetraploidy (62 and 25 million years ago) and the cultivated olive to a nearly present partial duplication event [31,32]. Ultimately, no AQP-type loss after duplication appears to have occurred.…”

Gene Expression Pattern in Olive Tree Organs (Olea europaea L.)

“…Reads were mapped to the Olea europaea cv. "Picual" genome as the reference Oleur061 [6]. Mapping was undertaken using parameters k-mer = 63 and 95% of matches.…”

“…sylvestris) and cultivars "Farga" and "Picual" have been assembled in the last 3 years [4][5][6]. In addition, 50 more genotypes, 40 cultivated and 10 wild trees, have been sequenced [6]. The "Picual" genome turned out to be more complex than previously reported genomes.…”

“…The development of genomic information and tools for breeders should now be possible because the genomes of wild olive trees (Olea europaea var. sylvestris) and cultivars "Farga" and "Picual" have been assembled in the last 3 years [4][5][6]. In addition, 50 more genotypes, 40 cultivated and 10 wild trees, have been sequenced [6].…”

Genetic Resources of Olea europaea L. in the Garda Trentino Olive Groves Revealed by Ancient Trees Genotyping and Parentage Analysis of Drupe Embryos

“…Whether admixture between the two wild ancestral olive pools (western and eastern oleasters) occurred before domestication or whether early domestication of the western wild oleaster took place followed by introgression from Q3 cultivars (Eastern Mediterranean) is still not clear [ 73 , 74 , 75 ]. However, a recent population analysis, based on a genome re-sequencing approach, supports the hypothesis of two independent events in olive domestication, including an early possible genetic bottleneck, and provides evidence that the clustering into different groups (a similar clustering of cultivated accessions into Q1, Q2 and Q3 groups was also observed with this approach) may indicate, not only a strong geographical component, but at the same time a possible phenotypic selection for traits such as fruit size [ 76 ]. Our population subdivision at K = 3 was congruent, as expected, with these three genepools and evidenced a high genetic diversity within cultivars putative from the Central Mediterranean Basin (Q2), especially from France, indicating a high admixture level as previously reported by [ 77 ].…”