The reactions of some Brussels sprout F1 hybrids and inbreds to cauliflower mosaic and turnip mosaic viruses

Abstract

SUMMARYVirus infection of Brussels sprout crops was widespread in Britain in 1974–76. Infected plants contained mostly cauliflower mosaic (CaMV) and turnip mosaic (TuMV) viruses but occasionally broccoli necrotic yellows virus (BNYV) was also found. The most seriously affected cultivar was the F1 hybrid cv. Fasolt. Other hybrids including cvs Achilles, Citadel and King Arthur were more tolerant of infection.A key was developed for assessing the reactions of various F1 hybrids and their parent inbred lines to CaMV + TuMV. Tests showed that the mean symptom severity of hybrids was usually less than the mean symptom severity of the parent inbreds, indicating that resistance to infection is partially dominant.The reactions of infected inbreds grown in winter under glasshouse conditions (15–18°C) were closely correlated with those of plants grown in the field. Thus, rapid selection of virus‐tolerant inbreds can be made under glasshouse conditions.