Olive

Abstract

Biochemical and molecular procedures have been developed for olive genotyping, for taxonomy between cultivated and wild olives, for phylogenetic studies of cultivars, and for identification of usable markers linked to the most important agronomic traits, such as size of the tree, flowering induction, apical dominance, productivity, self‐fertility, quantity and quality of oil and secondary products of fruit, biotic and abiotic resistance. These characters could be introgressed into cultivars by conventional breeding or through transgeny. Successful results by classical breeding are difficult to obtain due to the different flower fertility and the long juvenile period of the progenies. The low efficiency of modern genetic improvement techniques suggests that genetic transformation techniques could speed up the development of new genotypes; however, the development of efficient regeneration methods from mature tissue is the limiting factor for applying this technology, in olive. Transgenic olive plants with modified growth habit and putative induced disease resistance are under filed conditions to test their phenotype. Other attempts of genetic improvement such as clonal selection, mutation through γ‐irradiation, protoplast technology, haploid, changes in ploidy level, somaclonal variation, and somatic hybridization are discussed and reviewed.

Whole genome scanning of a Mediterranean basin hotspot collection provides new insights into olive tree biodiversity and biology

“…Olive tree cultivars have been planted nearby wild populations since ancient times, where they exchange pollen, which has resulted in effective crop production and historical hybridization (Rubio De Casas et al., 2006). Moreover, olive tree research and breeding have been limited by factors such as the time‐consuming process of constructing cross populations for genetic mapping, the long juvenile phase, and the high levels of heterozygosity (Rugini et al., 2016). Therefore, the recovery of genetic diversity and the identification of genetic regions of olive tree associated with important agronomic traits linked to phenology, yield, and quality of the oil have become fundamental, notably in the context of the growing environmental impact of climate change (Aydin et al., 2021; Skodra et al., 2021).…”