BackgroundDiseases caused by Pseudomonas syringae (Ps) are recognized as the most damaging factors in fruit trees with a significant economic and sanitary impact on crops. Among them, bacterial canker of apricot is exceedingly difficult to control due to a lack of efficient prophylactic measures. Several sources of partial resistance have been identified among genetic resources but the underlying genetic pattern has not been elucidated thus far. In this study, we phenotyped bacterial canker susceptibility in an apricot core-collection of 73 accessions over 4 years by measuring canker and superficial browning lengths issued from artificial inoculations in the orchard.In order to investigate the genetic architecture of partial resistance, we performed a genome-wide association study using best linear unbiased predictors on genetic (G) and genetic x year (G × Y) interaction effects extracted from linear mixed models.Using a set of 63,236 single-nucleotide polymorphism markers genotyped in the germplasm over the whole genome, multi-locus and multi-variate mixed models aimed at mapping the resistance while controlling for relatedness between individuals.ResultsWe detected 11 significant associations over 7 candidate loci linked to disease resistance under the two most severe years. Colocalizations between G and G × Y terms indicated a modulation on allelic effect depending on environmental conditions. Among the candidate loci, two loci on chromosomes 5 and 6 had a high impact on both canker length and superficial browning, explaining 41 and 26% of the total phenotypic variance, respectively. We found unexpected long-range linkage disequilibrium (LD) between these two markers revealing an inter-chromosomal LD block linking the two underlying genes. This result supports the hypothesis of a co-adaptation effect due to selection through population demography. Candidate genes annotations suggest a functional pathway involving abscisic acid, a hormone mainly known for mediating abiotic stress responses but also reported as a potential factor in plant-pathogen interactions.ConclusionsOur study contributed to the first detailed characterization of the genetic determinants of partial resistance to bacterial canker in a Rosaceae species. It provided tools for fruit tree breeding by identifying progenitors with favorable haplotypes and by providing major-effect markers for a marker-assisted selection strategy.Electronic supplementary materialThe online version of this article (10.1186/s12870-019-1631-3) contains supplementary material, which is available to authorized users.

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Selon l’étude de six pays de la région MENA, l’économie sociale et solidaire (ESS) comprend à la fois des entités à but lucratif et à but non lucratif, des coopératives, des associations et des mutuelles. Leurs cadres juridiques et leur impact économique, notamment en termes d’emploi et de contribution au PIB, sont étudiés. Les financements endogènes et exogènes, tels que l’épargne personnelle et les subventions, sont les principales sources d’EPE, qui sont confrontées à des déficiences structurelles dans le système bancaire et à l’absence de produits financiers adaptés que l’industrie de la microfinance devrait surmonter. L’ESS, y compris les institutions de microfinance, joue également un rôle dans la formalisation des entreprises informelles et des employés, ainsi que dans la création d’emplois, notamment pour les jeunes et les femmes.