Summary
The influence of wounding and high‐temperature treatment on the detection of iris severe mosaic virus (ISMV) in secondarily ISMV‐infected iris bulbs was studied. Wounding of the bulbs just after lifting, followed by storage for 3 wk at 17°C or 20°C, increased the detectability of ISMV to 100% reliability. High‐temperature treatment and consecutive storage at 17°C induced a similar improvement of detection. It is concluded that a certain degree of stress, such as wounding or high‐temperature treatment, ultimately leads to an increase in viral antigens and thus to improvement of detection. It is hypothesised that the virus titre increases by the altered metabolism during the repair reactions as a response to stress applied to the bulbs.