Development of a screening system to detect Xanthomonas campestris in seed and evaluation of pathogen resistance in seed parents of winter cauliflower

Black rot, caused by the bacterium Xanthomonas campestris pv campestris (Xcc), is a very serious problem on cauliflower in Cornwall.

This report describes a project on Xanthomonas campestris pv campestris in Cornish cauliflowers with specific objectives t-:-

• Evaluate seed test procedures
• Set up a seed-testing facility at Rosewarne
• Train staff at Rosewarne in seed-testing procedures
• Detect and quantify seed-borne infection in a selection of the most widely grown cultivars and infected seed which had been tested during the previous year
• Identify and race type isolates of Xanthomonas campestris pv campestris from seeds, crops and cruciferous weeds as a possible means of determining the source(s) of infection
• To carry out glasshouse resistance screening of a selection of the most widely-grown cauliflower cultivars