No abstract

The genus Phomopsis (teleomorph Diaporthe) comprises phytopathologically important microfungi with diverse host associations and a worldwide distribution. Species concepts in Phomopsis have been based historically on morphology, cultural characteristics and host affiliation. This paper serves to provide an overview of the current status of the taxonomy in Phomopsis with special reference to biology, applications of various species, species concepts, future research perspectives and names of common pathogens, the latter being given taxonomic reappraisal. Accurate species identification is critical to understanding disease epidemiology and in developing effective control measures for plant diseases. Difficulties in accurate species identification using morphology have led to the application of alternative approaches to differentiate species, including virulence and pathogenicity, biochemistry, metabolites, physiology, antagonism, molecular phylogenetics and mating experiments. Redefinition of Phomopsis/Diaporthe species has been ongoing, and some species have been redefined based on a combination of molecular, morphological, cultural, phytopathological and mating type data. Rapid progress in molecular identification has in particular revolutionized taxonomic studies, providing persuasive genetic evidence to define the species boundaries. A backbone ITS based phylogenetic tree is here in generated using the sequences derived from 46 type, epitype cultures, and vouchers and is presented as a rough and quick identification guide for species of Phomopsis. The need for epitypification of taxonomic entities and the need to use multiple loci in phylogenies that better reflect species limits are suggested. The account of names of phytopathogens currently in use are listed alphabetically and annotated with a taxonomic entry, teleomorph, associated hosts and disease symptoms, including brief summaries of taxonomic and phylogenetic research. Available type culture information and details of gene sequences derived from type cultures are also summarized and tabulated.

No abstract

The genus Diaporthe comprises pathogenic, endophytic and saprobic species with both temperate and tropical distributions. Cryptic diversification, phenotypic plasticity and extensive host associations have long complicated accurate identifications of species in this genus. The delimitation of the generic type species Diaporthe eres has been uncertain due to the lack of ex-type cultures. Species limits of D. eres and closely related species were evaluated using molecular phylogenetic analysis of eight genes including nuclear ribosomal internal transcribed spacer (ITS), partial sequences of actin (ACT), DNA-lyase (Apn2), translation elongation factor 1-α (EF1-α), beta-tubulin (TUB), calmodulin (CAL), 60s ribosomal protein L37 (FG1093) and histone-3 (HIS). The occurrence of sequence heterogeneity of ITS within D. eres is observed, which complicates the analysis and may lead to overestimation of the species diversity. The strict criteria of Genealogical Concordance Phylogenetic Species Recognition (GCPSR) were applied to resolve species boundaries based on individual and combined analyses of other seven genes except the ITS. We accept nine distinct phylogenetic species including helicis and D. pulla. Modern descriptions and illustrations are provided for these species. Newly designed primers are introduced to amplify and sequence the Apn2 (DNA-lyase) gene in Diaporthe. Based on phylogenetic informativeness profiles, EF1-α, Apn2 and HIS genes are recognised as the best markers for defining species in the D. eres complex.