Diversity of Pectobacteriaceae Species in Potato Growing Regions in Northern Morocco

Dickeya and Pectobacterium pathogens are causative agents of several diseases that affect many crops worldwide. This work investigated the species diversity of these pathogens in Morocco, where Dickeya pathogens have only been isolated from potato fields recently. To this end, samplings were conducted in three major potato growing areas over a three-year period (2015-2017). Pathogens were characterized by sequence determination of both thegapAgene marker and genomes using Illumina and Oxford Nanopore technologies. We isolated 119 pathogens belonging toP. versatile(19%),P. carotovorum(3%),P. polaris(5%),P. brasiliense(56%) andD. dianthicola(17%). Their taxonomic assignation was confirmed by draft genome analyses of 10 representative strains of the collected species.D. dianthicolawere isolated from a unique area where a wide species diversity of pectinolytic pathogens was observed. In tuber rotting assays,D. dianthicolaisolates were more aggressive than Pectobacterium isolates. The complete genome sequence ofD. dianthicolaLAR.16.03.LID was obtained and compared with otherD. dianthicolagenomes from public databases. Overall, this study highlighted the ecological context from which some Dickeya and Pectobacterium species emerged in Morocco, and reported the first complete genome of aD. dianthicolastrain isolated in Morocco that will be suitable for further epidemiological studies.