The Location of Sources of Field Resistance toBremia lactucaein WildLactucaSpecies

摘要

AbstractThirty‐one accessions of four Lactuca species (L. serriola, L. saligna, L. aculeata, L. squarrosa) and oneL. serriola×L. sativahybrid were screened for field resistance toBremia lactucae.In theL. serriolagroup, significant differences in the level of field resistance were distinguished. The accessions PI 281876 and PI 253467 were free of infection. Moreover, allL. salignaaccessions tested were totally free from disease during three‐year‐investi