Studying the aggressiveness of Sclerotinia sclerotiorum (Lib.) De Bary isolates from multiple hosts on tomato cultivars

Pathogenicity factor plays an eminent role in the infection process by the plant pathogen and determines the amount of loss that it can cause to the host plant. Sclerotinia sclerotiorum is a pathogen with multiple host crops and thus it becomes important to estimate the relation between the pathogenicity factor and the extent of damage it cause to the host plant. As the pathogen is majorly studied for its infection and losses in mustard but it also has severe impact on the vegetable crops as well, which is often neglected. Thus a study was conducted on the isolates of the pathogen from different host crops. Aggressiveness of the isolates was determined on the basis of lesion size using Detached leaf method and oxalic acid produced by the isolates was quantified. Commercial cultivars of tomato were also screened using the most aggressive isolate under glasshouse conditions to find the resistant one suitable for cultivation. Amongst all the tested isolates, Ss-TN was found to be the most aggressive isolate with highest oxalic acid production. The amount of oxalic acid produced by the isolates varied from 2.50mgL− 1 to 4.57mgL− 1 and the lesion size formation ranged from 6 to 25 mm. The study emphasised on the extent of damage, the most aggressive isolate can cause on commercial tomato cultivars under glass house conditions. The results showed that, cultivar Rich field, F1 Hybrid Tomato Super Action − 666, TO-1458 and Angad were moderately resistant to the pathogen and can be considered suitable for production. © Indian Phytopathological Society 2024.