Diaporthe species associated with postharvest fruit rot of kiwifruit in Anhui province, China

Diaporthe species are important pathogens, endophytes, and saprophytes on various plants. Although kiwifruit is an important host for this genus, the species occurring on kiwifruit remain largely unresolved. In this study, 75 Diaporthe isolates were isolated from 60 kiwifruit samples suspected of fruit rot disease collected in Anhui Province, China. Phylogenetic analyses based on five loci (ITS, cal, his3, tef1, and tub2) combined with morphology of 34 representative isolates showed that they belong to six Diaporthe species (D. arecae, D. biguttulata, D. eres, D. hongkongensis, D. sojae, and D. unshiuensis), distributed across three sections (Eres, Foeniculina, and Sojae). Of these, D. eres (38.7%), D. arecae (17.3%), and D. hongkongensis (14.7%) were the most prevalent species in Anhui Province. Pathogenicity tests on ‘Hongyang’ kiwifruit revealed varying aggressiveness among species and isolates, with D. unshiuensis and D. hongkongensis exhibiting strong pathogenicity, while D. sojae showed weaker pathogenicity. Subsequent verification of 18 previously reported species on kiwifruit confirmed 12 as valid species (D. actinidiicola, D. ambigua, D. eres, D. ganjae, D. hongkongensis, D. novem, D. passiflorae, D. psoraleae-pinnatae, D. rudis, D. sojae, D. tulliensis, and D. unshiuensis). This study represents the first reports of D. arecae, D. biguttulata, D. hongkongensis, D. sojae, and D. unshiuensis causing fruit rot on kiwifruit, and provides timely updates on the taxonomic status of Diaporthe species previously reported on kiwifruit, thereby offering valuable information for the disease control of kiwifruit.