Mycorrhiza-mediated physiological responses of shallot against twisted disease and drought stress

Shallot, a strategic horticultural commodity in Indonesia, is susceptible to biotic stress (e.g., twisted disease) and abiotic stress (e.g., drought). Mycorrhizal fungi offer an environmentally friendly solution to enhance plant resilience. This study evaluated the effects of mycorrhizal application on shallot plants against twisted disease (Fusarium acutatum) and drought stress. Using a randomized complete block design, we assessed growth, disease resistance, and physiological responses. Data were analyzed using analysis of variance followed by Tukey’s honestly significant difference test at a 95% confidence level. Results indicated that mycorrhizal application reduced both the severity and rate of twisted disease development in shallots. It also maintained leaf chlorophyll and carotenoid levels, physiological functions, and growth under both optimal and drought-stress conditions. Principal components analysis showed an antagonistic relationship between disease severity and photosynthetic pigments, suggesting F. acutatum impairs photosynthesis. Additionally, proline levels showed trade-offs with water content and phenolics, potentially reflecting stress-induced resource allocation shifts. Pearson correlation analysis confirmed interconnected biosynthetic pathways for stress-responsive metabolites. This study underscores the potential of mycorrhizal fungi to bolster shallot resilience against disease and drought, offering valuable insights for sustainable agricultural practices.