Ahmed El Bakkali

Institut National de la Recherche Agronomique, INRA, Maroc · APCRPG

Olive leaf spot (OLS), caused by Fusicladium oleagineum, is a significant disease affecting olive orchards, leading to reduced yields and compromising olive tree health. Early and accurate detection of this disease is critical for effective management. This study presents a comprehensive assessment of OLS disease progression in olive orchards by in...

Olea europaea L. is one of the most widespread tree crops in the Mediterranean Basin and the high genetic and phenotypic diversity of cultivars reflects the long evolutionary history of the species in the region. We assessed the intraspecific variability of 83 olive cultivars from different Mediterranean countries, by screening leaf and stem traits...

Olive (Olea europaea, subsp. europaea, var. europaea) is an iconic tree of the Mediterranean area. One major consequence of climate change is the increasing temperatures. Rising temperatures impact flowering time and synchronization, potentially affecting pollination success. This may negatively impact fruit production in olive trees. Studying the...

Flowering date in perennial fruit trees is an important trait for fruit production. Depending on the winter and spring temperatures, flowering of olive may be advanced, delayed, or even suppressed. Deciphering the genetic control of flowering date is thus key to help selecting cultivars better adapted to the current climate context. Here, we invest...

Flowering date in perennial fruit trees is an important trait for fruit production. Depending on the winter and spring temperatures, flowering of olive may be advanced, delayed, or even suppressed. Deciphering the genetic control of flowering date is thus key to help selecting cultivars better adapted to the current climate context. Here, we invest...

Crop-to-wild gene flow is a mechanism process widely documented, both in plants and animals. This can have positive or negative impacts on the evolution of admixed populations in natural environments, yet the phenomenon is still misunderstood in long-lived woody species, contrary to short-lived crops. Wild olive Olea europaea L. occurs in the same...

Olive leaf spot (OLS), also called olive scab and peacock eye, caused by Fusicladium oleagineum, is a major disease that causes significant damage to olive trees. However, we still lack information about how cultivar and environmental factors influence disease development. In this study, evaluation of the incidence and severity on twenty olive cult...

Admixtures between wild animals and plants and their domesticated relatives are widely documented. This can have positive or negative impacts on the evolution of admixed populations in natural environments, yet the phenomenon is still misunderstood in long-lived woody species, contrary to short-lived crops. Wild olive Olea europaea L. occurs in the...

Delineating chilling and forcing periods is one of the challenging topics in understanding how temperatures drive the timing of budburst and bloom in fruit tree species. Here, we investigated this question on olive trees, using flowering data collected over six years on 331 cultivars in the worldwide collection of Marrakech, Morocco. Using a Partia...

Delineating chilling and forcing periods is one of the challenging topics in understanding how temperatures drive the timing of budburst and bloom in fruit tree species. Here, we investigated this question on olive trees, using flowering data collected over six years on 331 cultivars in the worldwide collection of Marrakech, Morocco. Using a Partia...

Delineating chilling and forcing periods is one of the challenging topics in understanding how temperatures drive the timing of budburst and bloom in fruit tree species. Here, we investigated this question on olive trees, using flowering data collected over six years on 331 cultivars in the worldwide collection of Marrakech, Morocco. Using a Partia...

Precision Agriculture (PA) is a management strategy based on Information and Communication Technologies (ICT) used to assist management decisions with the aim to increase productivity, to reduce labor time and inputs needed, to improve benefits and to protect the environment. Techniques related to PA were initially used to monitor status of annual...

The Laperrine’s olive is endemic to the Saharan Mountains. Adapted to arid environments, it may constitute a valuable genetic resource to improve water-stress tolerance in the cultivated olive. However, limited natural regeneration coupled with human pressures make it locally endangered in Central Sahara. Understanding past population dynamics is t...

Conservation and use of well-characterized olive (Olea europaea L.) genetic resources are the key to future olive improvement and sustainable production. Yet, authentication of plant materials in ex-situ olive collections throughout the world has received little attention. Here we characterized 95 accessions, from a collection maintained in the exp...

Molecular characterization of crop genetic resources is a powerful approach to elucidate the origin of varieties and facilitate local cultivar management. Here we aimed to decipher the origin and diversification of French local olive germplasm. The 113 olive accessions of the ex situ collection of Porquerolles were characterized with 20 nuclear mic...

Olive (Olea europaea L.) is a major fruit crop in the Mediterranean Basin. Ex-situ olive management is essential to ensure optimal use of genetic resources in breeding programs. The Worldwide Olive Germplasm Bank of Córdoba (WOGBC), Spain, and Marrakech (WOGBM), Morocco, are currently the largest existing olive germplasm collections. Characterizati...

Knowledge on the crop domestication process is important from a cultural and agricultural standpoint since it can shed light on the origin and history of human civilizations as well as the management of genetic resources, while offering guidance for modern breeding. The olive tree ( Olea europaea ssp. europaea ) is the most iconic of the old crop s...

Background Plant-parasitic nematodes (PPN) are major crop pests. On olive (Olea europaea), they significantly contribute to economic losses in the top-ten olive producing countries in the world especially in nurseries and under cropping intensification. The diversity and the structure of PPN communities respond to environmental and anthropogenic fo...

The olive (Olea europaea L.) is a typical important perennial crop species for which the genetic determination and even functionality of self-incompatibility (SI) are still largely unresolved. It is still not known whether SI is under gametophytic or sporophytic genetic control, yet fruit production in orchards depends critically on successful ovul...

Investigating when, where, and how domestication took place is crucial for understanding cultural and evolutionary transitions in the history of crop species. The olive (Olea europaea subsp. europaea) is often considered the most iconic tree of the Mediterranean Basin, probably domesticated in the Levant 6000 years ago. Recent genetic study has sug...

The relative importance of seeds and pollen genes flow in olive’s varieties diversifica- tion and the somatic mutations accumulated during the history of the vegetative spread of olive’s varieties in the Mediterranean Basin are presented according to a parentage analysis approach. For cultivated olive trees, the new genotypes issued from cross be-...

Low density of an unknown root-knot nematode was found on wild olive soils at Cape Spartel near Tanger city in northern Morocco. Morphometry, esterase and malate dehydrogenase electrophoretic phenotypes, as well as ribosomal DNA (rDNA) and mitochondrial DNA (mtDNA) sequences demonstrated that this nematode species differs clearly from other previou...

. The use of the molecular markers (nuclear and chloroplastic microsatellites) allowed us to assert that the variety Picholine Morocaine (PM) is the result of a secondary diversification by successive crosses between domesticated introduced genotype from the Eastern Mediterranean with Local wild olive trees in Western Mediterranean Basin. PM variet...

Plant-parasitic nematodes (PPN) significantly contribute to economic losses in the top-ten olive producing countries, especially in the Mediterranean basin. Instead of controlling the main pathogenic nematode species as usual, one innovative strategy to control PPN would be to manage diversity in communities in order to lead them to be less pathoge...

Despite the socio-economic importance of olive oil and the need of olive breeding, genetic studies on agronomic traits are restricted to few biparental populations limiting the efficiency of QTL (Quantitative Trait Loci) mapping strategy. Association mapping based on a diversified collection of olive germplasm can be proposed as a complementary str...

Plant-parasitic nematodes significantly contribute to economic losses in the ten top olive producing countries in the world, especially in the Mediterranean basin (Spain, Italy, Greece, Tunisia, and Morocco). Diversity and structures of plant-parasitic nematode communities respond to evolutionary, environmental and anthropogenic forces. Instead of...

The wild olive distribution extends from the Mediterranean region to south Asia and Austral Africa. The species is also invasive, particularly in Australia. Here, we investigated the sequence variation at five nuclear single-copy genes in 41 native and invasive accessions of the Mediterranean and African olive subspecies. The nucleotide diversity w...

The wild olive distribution extends from the Mediterranean region to south Asia and Austral Africa. The species is also invasive, particularly in Australia. Here, we investigated the sequence variation at five nuclear single-copy genes in 41 native and invasive accessions of the Mediterranean and African olive subspecies. The nucleotide diversity w...

Background and AimsThe olive (Olea europaea subsp. europaea) was domesticated in the Mediterranean area but its wild relatives are distributed over three continents, from the Mediterranean basin to South Africa and south-western Asia. Recent studies suggested that this crop originated in the Levant while a secondary diversification occurred in most...

Selecting desired agronomic traits may lead to a loss of genetic diversity in crop species. A molecular investigation was conducted to determine how well a set of olive (Olea europaea L.) accessions sampled in Moroccan traditional orchards represented the entire Moroccan olive diversity range. We therefore collected, in traditional agroecosystems f...

In order to highlight the genetic status and origin of Moroccan apricot populations, trees were collected from ten oasis agroecosystems and analysed with AFLP markers. A total of 87 accessions and 12 cultivars grown in Moroccan orchards, including 'Canino' and 'Del Patriarca' cultivars, were surveyed and compared with in situ Tunisian and ex situ M...

Phenotypic characterisation of germplasm collections is a decisive step towards association mapping analyses, but it is particularly expensive and tedious for woody perennial plant species. Characterisation could be more efficient if focused on a reasonably sized subset of accessions, or so-called core collection (CC), reflecting the geographic ori...

Plot of ad-hoc ΔK measurements and coefficients of similarity (H′) for K between 2 and 7. Arrows indicate the best genetic structure model for both core collections and OWGB Marrakech. According to both parameters, i.e. ΔK and H′, the best genetic structure model was not stable, while it is defined at K = 3 in Marrakech OWGB, indicating the absence...

Maximizing average Cavalli-Sforza & Edwards genetic distance (DCE) and allelic coverage (Cv). Values of DCE and Cv were maximized simultaneously with respect to a weight assigned to each measure. The Core Hunter program was run independently for 10 different weight values assigned to DCE and Cv measures; (1) When a weight of 100% was assigned to Cv...

Three different levels proposed for core collections. Level 1 (L1) represents the primary core collection (CC50), which includes the 40 entries selected using the “Sh strategy” implemented in Core Hunter program at 8%, two varieties carrying the two missing cpDNA haplotypes, and 8 non-selected reference varieties among the 14. Level 2 includes acce...

List of 502 genotypes used in the present study classified according to distinct genotypes (SSR profiles), origin, maternal lineage and inferred ancestry (Q matrix) at K = 3 clusters. (XLS)

Protocols of nuclear and chloroplast loci analyses. (DOC)

Genetic analysis of OWGB Marrakech. (DOC)

Inferred structure for K = 5 clusters within OWGB Marrakech, CC50, and CC94 core collections. H′ represents the similarity coefficient between runs, and ΔK represents the ad-hoc measure of Evanno et al. [84]. No consistency was observed in genetic structures based on more than three clusters. (TIF)

List of traits, number of trait classes according to standards described by the International Olive Oil Council, and number of varieties with available phenotypic data. The number of varieties differed according to traits indicates that there was missing data, and that not all varieties were completely characterized with the 72 phenotypic traits. (...

Genetic parameters of core subsets sampled using four different strategies with the ASLS method at four sample sizes, i.e. 4, 8, 24, and 32%. The CC2-40 core subset (in bold) was chosen as the optimal to construct final core collections. (DOC)

List of 200 core collections with a 94 sample size (CC94) generated with Mstrat using the core collection of 50 entries as a kernel (CC50). (x) Corresponds to the presence of the accession in the core collection concerned. The CC level column indicates the level of the core collection as shown in Figure S2. No differences between the 200 cores were...

The location and timing of domestication of the olive tree, a key crop in Early Mediterranean societies, remain hotly debated. Here, we unravel the history of wild olives (oleasters), and then infer the primary origins of the domesticated olive. Phylogeography and Bayesian molecular dating analyses based on plastid genome profiling of 1263 oleaster...

Evaluation of genetic diversity is of great interest for the management of germplasm collections and breeding programs. Management can be efficient when the evaluation is focused on a subset of accessions that represents the variability observed in the whole germplasm collection. Most core sets have been developed for seed crops using different app...

The conservation of cultivated plants in ex-situ collections is essential for the optimal management and use of their genetic resources. For the olive tree, two world germplasm banks (OWGB) are presently established, in Córdoba (Spain) and Marrakech (Morocco). This latter was recently founded and includes 561 accessions from 14 Mediterranean countr...