| Popis: |
The virulence phenotype of two isolates of the downy mildew pathogen, Peronospora parasitica , one from oilseed rape, and the other from cauliflower was assessed by controlled inoculation of seedlings from a wide range of different cultivated forms of Brassica species. Both isolates were capable of infecting species other than their original host, while the rape isolate was found to be virulent on a significant proportion of the horticultural brassicas tested. The isolates were heterothallic and capable of forming oospores in 25 out of the 47 hosts utilized. The implications of these findings for the epidemiology of the pathogen in the field are discussed. |
