Diaporthe xiuwenensis sp. nov, a new fungal species causing postharvest kiwifruit rot in Guizhou

Diaporthe spp. (including their asexual Phomopsis states) are important plant pathogens found widely in different host plants, such as pathogens, endophytes or saprobes. In this study, a new species of Diaporthe causing fruit rot in kiwifruit, Diaporthe xiuwenensis sp. nov was isolated from kiwifruit with apparent soft rot symptoms during storage in Guizhou Province, China. Identification was made using morphology and comparison of DNA sequence data of the nuclear ribosomal ITS (internal transcribed spacer) + tef1 (translation elongation factor-1α) + tub2 (β-tubulin) + cal (calmodulin) + his (histone H3) gene regions. This study further described a new Diaporthe species and discussed its morphology and phylogenetic relationships with other Diaporthe species. Koch's postulates tests identified the causative agents of kiwifruit soft rot. The results of pathogenicity test showed that Diaporthe xiuwenensis sp. nov was pathogenic to kiwifruit, and the Koch's postulates were completed.