Downy mildew resistance and genetic variability in a wild rocket germplasm collection

One hundred accessions of a “core collection” Diplotaxis tenuifolia (L.) DC. and Eruca spp. were screened at seedling stage for resistance to downy mildew. Accessions tested the assigned 0–6 interaction phenotypes. All cultivated rocket (Eruca spp.) exhibited resistant (R) response both in cotyledons young leaves. The wild (D. tenuifolia) higher susceptibility than 1st 2nd leaves, with 16 47 classified as or partially (PR) cotyledon leaves stages, respectively. Only three displayed an R phenotype most frequent vs. was highly susceptible/susceptible (HS/S) combination (33 accessions), followed by S/PR (18 accessions). A significant correlation (r = 0.917, P < .000) observed between disease index molecular markers analyses revealed wide genetic distance Eruca, which gather two clearly separated species clusters. variability is accompanied diversity interactions pathogen isolate. closest similarities among D. found provided same breeding company. Future studies will be focused on main objectives: (a) assessment behavior that have evidenced R/R, S/PR, HS/PR leaf under greenhouse field production (b) genome mapping features provide mildew resistance.