Conclusions
In this study we explored the genetic diversity, population structure, and host differentiation of 95 individuals from 10 populations ofO. crenata collected from different locations and crop hosts in Algeria using GBS derived markers. A set of 8,004 high-quality SNPs was generated for the genetic diversity analyses. The study revealed low to moderate genetic differentiation between close and geographically separated populations, respectively. Population differentiation by geographic distance was more evident across crop hosts as supported by phylogenetic and clustering analyses. Four genetic pools were differentiated, clustered according to crop hosts. AT and BM (Blida-Mouzaia) populations were shown to be spatially and genetically isolated. This study suggests that O. crenata populations in Algeria are adapting locally and that host specificity could arise in some populations.