Nutrient utilization and degradative enzyme activity of the dragon fruit canker pathogen, Neoscytalidium dimidiatum.

Dragon fruit canker (DFC), caused by Neoscytalidium dimidiatum, is a major disease affecting dragon fruit production. However, the pathogen's nutrient utilization strategies and enzymatic activities remain poorly characterized. Using calcofluor white-based fluorescence microscopy, we show that nutrient limitation restricts fungal growth and development, impairing melanization and arthrosporulation. Carbon utilization assays revealed a preference for maltose, suggesting adaptation to starch-derived sugars. Nitrogen utilization assays indicated efficient assimilation of complex organic nitrogen sources. In addition, we experimentally validated extracellular enzymatic activities involved in host macromolecule degradation, including cellulase, amylase, pectinase and protease activities. Together, these findings provide insight into the physiological traits of N. dimidiatum associated with growth and development under varying nutrient conditions.