Comparative analysis of inoculation methods for inducing bacterial wilt in Ralstonia solanacearum susceptible tomato hosts

Abstract

Bacterial wilt, caused by Ralstonia solanacearum, is a devastating vascular disease affecting a wide range of crops, including tomato (Solanum lycopersicum), with serious implications for global food security. Effective and reproducible inoculation methods are critical for understanding host-pathogen interactions, evaluating cultivar resistance, and developing disease management strategies. This study compared the efficiency of four common inoculation techniques—stem injection, root cutting, root dipping, and soil drenching—in inducing bacterial wilt in susceptible tomato plants under controlled greenhouse conditions. Parameters assessed included disease severity progression, infection rate, disease incidence, and pathogen recovery. Results showed that stem injection was the most effective method, producing 100% infection and the most rapid disease progression, with severe symptoms observed by 8 days post-inoculation (dpi). Root cutting also led to high infection (85%) and symptom development by 8 dpi. Root dipping resulted in moderate infection (75%) with slower progression, while soil drenching had the lowest infection rate (60%) and slowest disease development. Pathogen recovery rates mirrored these trends, with the highest recovery from stem-injected and root-cut plants. These findings highlight the significant influence of inoculation technique on disease development and underscore the need for standardized methods in bacterial wilt research to ensure accurate screening and reproducible results.