An insight into bacterial wilt of eggplant—A review

Eggplant is considered as a prominent vegetable crop for its high amount of mineral content and widely cultivated in tropical and subtropical regions. The crop is susceptible to many diseases and one of the most harmful pathogens affecting eggplant production at global level is Ralstonia solanacearum, an aerobic non-spore-forming, Gram-negative, soil-inhabiting bacteria causing wilt. Attempts were made to manage this disease in the field through cultural, chemical and biological methods, however, satisfactory results could not be achieved due to wide host range and survival of the bacteria in soil for several years. Progress on developing disease resistant cultivars through hybridisation and grafting of commercial cultivars with resistant rootstock like Solanum torvum are effective to combat the wilt. Recent developments in biotechnology were also used to identify the molecular-marker linked with disease resistance for marker assisted breeding and to study the molecular mechanisms associated with resistance. There is still much to learn about the molecular mechanisms causing resistance and the roles played by R. solanacearum effectors. Hence, understanding of pathogen biology and behaviour are essential before designing any effective management strategy. This review updates information on R. solanacearum symptomatology, pathogen biology, diversity, pathogenicity, recent development in detection, management options such as resistant sources, breeding and biotechnological approaches to develop resistant eggplant for successful control of disease in the field.