Marine diatrypaceous fungi are associated with many host species, including Avicennia spp., Halosarceia halocnemoides (Nees) Paul G.Wilson, Kandelia candel (L.) Druce, Salicornia sp., Rhizophora apiculata Blume and Suaeda fruticosa (L.) Forssk. Accurate morphological identification of individual taxa of this family is difficult, as previous classifications generally lack sequence data. We provide a detailed account of all known marine diatrypaceous taxa and determine their phylogenetic and morphological relationships. A novel genus Halocryptovalsa Dayarathne & K.D.Hyde, gen. nov. is established to accommodate Halocryptovalsa salicorniae Dayarathne & K.D.Hyde, sp. nov., and Halocryptovalsa avicenniae, comb. nov. (synonym of Cryptovalsa avicenniae). Three novel species Cryptosphaeria avicenniae Devadatha & V.V.Sarma, sp. nov., Cryptosphaeria halophila Dayarathne & K.D.Hyde, sp. nov., and Diatrype mangrovei Dayarathne & K.D.Hyde, sp. nov., are introduced from mangroves. Halodiatrype is amended with asexual morph characters.

During the ongoing investigation of bambusicolous ascomycetous fungi in Yunnan, China, 24 specimens belonging to the family Roussoellaceae were collected and identified based on morphological features and phylogenetic support. Maximum-likelihood (ML) analyses and Bayesian analyses were generated based on the combined data set of ITS, LSU, tef1, and rpb2 loci. The phylogenetic analyses revealed four novel lineages in Roussoella s. str.; thus, we introduced four new species viz., Roussoella multiloculate sp. nov., R. papillate sp. nov., R. sinensis sp. nov., and R. uniloculata sp. nov. Their morphological characters were compared with the known Roussoella taxa, which lack sequence data in the GenBank. Asexual morphs of R. kunmingensis and R. padinae were recorded from dead bamboo culms in China (from the natural substrates) for the first time. Neoroussoella bambusae, Roussoella japanensis, R. nitidula, R. padinae, R. scabrispora, and R. tuberculate were also reported as the first records from China. All new taxa are described and illustrated in detail. Plates are provided for new reports.

Fungi are a large group of eukaryotes found as saprophytes, pathogens or endophytes, which distribute in every corner of our planet. As the main pathogens, fungi can cause 70–80% of total plant diseases, leading to huge crop yield reduction and economic loss. For identification of fungal plant pathogens, mycologists and plant pathologists have mainly gone through two stages, viz. morphological observation and morphology/phylogeny, and the next era might be utilizing DNA barcodes as the tool for rapid identification. This chapter accounts i) the brief history of development for fungal identification tools and main concepts, ii) the importance and confusion of “One fungus, one name” for pathogen identification, iii) more or fewer species that we need in agricultural practice, and iv) the foreground of fungal plant pathogen identification. These will help to solve the practical problems of identification of fungal pathogens in agricultural production.

The Karst landform is the main geographic characteristic in South China. Such areas are rich in vegetation and especially suitable for growth of shrubs and herbaceous plants. In this study, 11 Septoria strains were obtained from different plants’ leaves collected in the Kunming Botanical Garden, Yunnan Province, China. Based on single-gene and multi-gene analyses of five gene loci (tef1, rpb2, tub2, ITS, and LSU) and four gene regions (without LSU), these strains were found to belong to three independent phylogenetic lineages representing five species, including four novel taxa, and one new record for China. Five single gene trees were also provided to evaluate the effectiveness of each gene for discriminating the species, as a result of which tub2 was found to have the most suitable DNA barcode for rapid identification. Morphological descriptions, illustrations, and comparisons are provided for a more comprehensive assessment. Genealogical Concordance Phylogenetic Species Recognition (GCPSR) with a pairwise homoplasy index (PHI) test was used to evaluate the conclusions of the phylogenetic analyses.