Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

First record of verticillium wilt (Verticillium longisporum) in winter oilseed rape in the UK.

Abstract

V. longisporum is an important pathogen of oilseed rape (OSR) and vegetable brassicas in several European countries, but has not been reported previously in the UK. In 2007, Verticillium wilt was suspected in UK crops of winter OSR (W-OSR) on cultivar Castille in Romney Marsh, Kent and on cultivar Barrel near Hereford. At these two locations, 32 and 10% of the plants, respectively, appeared to be affected, but the presence of stem canker may have masked some infections. Symptoms were first seen as the crops began to ripen (seeds green-brown to brown, growth stage: 6.4-6.5) and included brown and dark grey vertical bands on the stems from soil level into the branches, and premature ripening of some branches. In June 2008, infection of W-OSR crops in different fields on the same farms was found on cultivar Es Astrid in Kent (56% incidence) and on cultivar Lioness in Hereford (15% incidence). The Kent farm had been growing W-OSR alternating with winter wheat for at least 10 years whilst the Hereford farm had grown W-OSR one year in four. These short rotations of OSR may be contributing to the appearance of this disease. This study confirms the identification of V. longisporum for the first time in the UK, through molecular studies (PCR assay and sequence analysis of the internal transcribed spacer regions) and detailed spore measurements that were not reported in an earlier review.