An Overview of Characterization and Identification of Soft Rot Bacterium Erwinia in Some Vegetable Crops

Vegetables play an important role in human nutrition and diet by supplying the much needed vitamins, minerals, and fibers. However, this important contributor to human diet is constraint by challenges especially rotting caused by phytopathogens. Erwinia species is one of the most destructive diseases threatening vegetables and resulting in the decay of the produce both in the field, storage and on transit. The soft rot pathogen has a wide host range and attack crops of almost all families causing greater economic losses than any other bacterial disease. The pathogen penetrates its host basically through wounds and natural openings such as stomata, lenticels and hydathodes and releases an arsenal of plant cell-wall degrading enzymes such as cellulose, zylanase, polygalacturanase (PG) and pectin-methyl esterases (PME) causing the maceration of the middle lamella and subsequently cell death. Decay is favoured by high temperature and humidity. Transmission is by water, insects and from infected plants to uninfected plants especially during harvesting and storage when uninfected produce are exposed to contamination by infected ones. This article provides first-hand information to students, researchers and agriculturists about the soft rot pathogen, its mode of action, predisposing factors, host range, means of transmission and control measures.