The investigation of the biology of the rose Blackspot fungus, Diplocarpon rosae leading to improved methods of control

摘要

Isolates of Diplocarpon rosae derived from a variety of rose types (climbers, ramblers etc.) were obtained from the UK and overseas. The morphology of the fungus was analysed, comparing colony colour and spore length and width. The genetic diversityof the fungus was also studied using molecular analysis techniques. Epidemiological studies were also carried out. Three distinct variations in colony colour between isolates were found: yellow, pale/dark brown and olive green. Conidial lengths among isolates varied between 11.1#mu#m and 30.7#mu#m. There was also a relationship between colony colour and conidial size, the longer conidia being associated with a lighter yellow colonies and the smaller conidia with dark colonies. Preliminary analysis of the results suggests that there is a correlation between colony colour, conidial size, molecular type and geographical origin but not between the rose type and geographical location within the UK.