Comparison of effects on chlorophyll content and growth between four Solanaceae crops inoculated with Pseudomonas syringae pv. syringae and Pectobacterium Carotovorum subsp. Carotovorum

Eggplant, potato, tomato and chilli pepper are susceptible to pathogens like Pseudomonas syringae and Pectobacterium carotovorum. The comparative differences in effects of these pathogens on their host crops are unknown, and therefore, this study aimed to investigate whether these different Solanaceae crops exhibit differential responses to these common pathogens and attempted to preliminarily explain these crop differences focussing on impact on several growth and physiology parameters. Crop comparisons were descriptive rather than statistical. A correlation analysis of the measured parameters was also performed. Correlation patterns within one crop were described and compared to other crops to further analyze differential pathogen responses across crops. The genus Solanum, potato and tomato, was mostly affected by the pathogens followed by Capsicum, chilli pepper, and another Solanum plant, eggplant, was the least affected. No clear correlation signature was established however, a few pairings were found between the Solanum with some exclusion of chilli pepper. This is the first study to assess P. syringae and P. carotovorum pathogen responses in four Solanaceae crops with comparisons between crops. Two bacterial species and one cultivar per crop were included in the current study and the authors advise that conclusions drawn from this study can only be applicable to the bacterial strains, crop and cultivars included. However, this study provides unique insights in crop performance under biotic stress, it opens a new avenue for investigation, setting a benchmark for future studies in crop-to-crop comparison of responses to pathogen inoculation.