Microclimatic parameters affect Cladosporium rot development and berry quality in table grapes

Cladosporium cladosporioides is an emerging pathogenic fungus that causes Cladosporium rot in postharvest table grapes ( Vitis vinifera). However, studies investigating the infection process of C. cladosporioides are lacking. Therefore, this study aimed to elucidate the infection process by investigating the influence of microclimatic parameters (temperature, wetness and fungal age) in C. cladosporioides pathogenesis, activities of grape defense-related enzymes and grape quality during the infection. C. cladosporioides effectively infects grapes by developing distinct colonies on the artificial wounds and berry surfaces, completing its life cycle within 48 h. The C. cladosporioides disease incidence optimally occurred at 20 degrees C and 25 degrees C. Wetness played an influential role in the infectivity of C. cladosporioides and 7-day-old C. cladosporioides resulted in the most serious disease incidence of table grapes. As a result of infection, the quality of grapes was affected, including berry weight, pH, titratable acidity (TA), total soluble solids (TSS), and ascorbic acid level. This infection also induced defense-related enzymes, including polyphenoloxidase (PPO), peroxidase (POD), phenylalanine ammonialyase (PAL), and catalase (CAT), at certain times. The findings of this study demonstrated that Cladosporium rot development depended on the microclimatic parameters of grapes, significantly affected the grape quality and induced grape's defense-related enzymes.

Automated summary

This study investigated the infection process of C. cladosporioides and its impact on grape quality and defense-related enzymes. The results showed that C. cladosporioides effectively infects grapes at optimal temperature and wetness, completing its lifecycle within 48 hours. The infection also resulted in a decrease in grape quality and induced the activity of defense-related enzymes at certain time points.