Black Rot of Crucifers and Sources of Resistance in Brassica Crops

Abstract

Since the early 1990s, diseases caused by Xanthomonas campestris have been spreading on new host plants and in new regions, that had not been previously affected by the pathogen. Still, vegetable crops of Brassica oleracea are the most damaged plants by black rot. Recent achievements in the studies on resistance to black rot were reviewed. For the first time resistance genes were identified based on gene-for-gene interaction with different races of the pathogen. Some East Asian cabbage and Portuguese Penca kale cultivars seemed to carry the homologous genes for race-specific resistance. Their origin in Asian cabbages was traced to the Flat Dutch group of varieties and to heading Mediterranean kale. It is suggested that novel non-specific stem resistance found in Chinese kale, broccoli and cabbage might be an alternative means of genetic protection against the pathogen. Discipline: Plant disease/Plant breeding Additional key words: race-specific resistance, race structure, leaf spot diseases