Diaporthe melongenae sp. nov, a new fungal species causing leaf blight in eggplant

Eggplant is a vegetable crop of the Solanaceae family. In November 2021, leaf blights of eggplant were observed from an eggplant field with an approximate disease incidence of 10%-30% in Cavite, Philippines. The infected leaves had typical symptoms of Phomopsis blight disease. Two fungal isolates were obtained, and morphological characteristics resemble those of a Diaporthe species. Based on the combined multi-gene phylogenetic analysis, Diaporthe melongenae sp. nov. formed a separate clade from closely related species: D. guangdongensis, D. melonis and D. moriniae with high bootstrap support values of 99/1.0 ML/PP. Moreover, the morphological characteristics of D. melongenae have differences from the closely related species. D. melongenae differs by having a slightly smaller average alpha conidial size than D. guangdongensis and absence of beta conidia. Diaporthe melonis is distinct from D. melongenae by having slightly constricted middle alpha conidia. Together, based on morphology, multi-locus phylogeny, GCPSRA and ecology (lifestyle, host and pathogenicity) herein we introduce D. melongenae as a novel species. Furthermore, this study presented the current phylogenetic tree of D. sojae species complex based on accepted Diaporthe species.