Etiology of postharvest fungal decay in kumquat: A polyphasic approach integrating aggressiveness, iPBS and SCoT fingerprinting, and multilocus phylogeny

Alkan M., Ozer G., Turkkan M., Bozoglu T., Erper S., Yıldırım E., ...Daha Fazla

POSTHARVEST BIOLOGY AND TECHNOLOGY, cilt.233, 2026 (SCI-Expanded, Scopus)

Özet

As the global popularity of kumquat (Fortunella spp.; syn. Citrus japonica) continues to rise, knowledge of the pathogens responsible for postharvest losses remains limited. This study presents the first etiological investigation of postharvest fungal decay in kumquat, using a multi-regional survey and polyphasic characterization. A pathogenic complex responsible for postharvest decay was identified on this host for the first time, consisting of Alternaria alternata (n = 23), Geotrichum citri-aurantii (n =17), Penicillium digitatum (n = 30), P. italicum (n = 8), and P. expansum (n = 4). Identification combined morphological characterization with high-resolution molecular fingerprinting using start codon targeted (SCoT 32) and inter-primer binding site (iPBS 2395) markers, yielding polymorphic profiles that provided clear species-level discrimination consistent with multilocus phylogenetic analysis. In vitro assays identified distinct thermal optima for each pathogen. Geotrichum citri-aurantii growth was maximal at 30 degrees C, whereas P. expansum grew optimally at 20 degrees C. The remaining species-P. digitatum, P. italicum, and A. alternata-all achieved maximum growth at 25 degrees C, although P. italicum demonstrated a broad optimal range spanning from 20 to 25 degrees C. Aggressiveness varied among the pathogens, with P. digitatum and A. alternata being the most aggressive, followed by G. citri-aurantii and P. expansum, while P. italicum was the least aggressive. This study establishes the first pathogenic profile for kumquat decay, providing a framework for evidence-based postharvest management. The demonstrated efficiency of SCoT 32 and iPBS 2395 markers highlights their value as powerful, rapid, and cost-effective tools for pathogen surveillance and taxonomic resolution in postharvest pathology.