Browsing by Author "Daranagama, D. A. D. A."

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Towards a natural classification and backbone tree for Xylariaceae recognized from multigene phylogeny and taxonomy.
(International Research Symposium on Pure and Applied Sciences, 2017 Faculty of Science, University of Kelaniya, Sri Lanka., 2017) Daranagama, D. A. D. A.; Liu, X. Z.; Hyde, K. D.
The family Xylariaceae, comprising over 1300 species, is considered as one of the largest families of the Ascomycota. Members of Xylariaceae exhibit a wide distribution and they are cosmopolitan. The objective of this study was to infer the evolutionary relationships among the species of the Xylariaceae based on multigene analysis including protein coding genes and to construct a backbone tree for the family. Combined analyses of ITS, LSU, RPB2 and β-tubulin sequence data were used to reconstruct the molecular phylogeny of Xylariaceae. Generic and familiar boundaries were revised and presented in an updated combined phylogenetic tree. A reliable phylogenetic and taxonomic relationship was utilized and a unified nomenclature for the genera by linking their asexual morphs with the respective sexual morphs was established. The generated phylogram was highly supported and showed well-resolute relationships within the Xylariaceae supported by morphology. This study confirmed the assumed separation of the genus Anthostomella and showed that the genus consists of six lineages, comprising several genera within Xylariaceae. This study provided an updated outline for the core Xylariaceae genera, which can easily be followed in the future applications. The morphological characters were redefined and limited only to include true Xylariaceae species. Based on the preliminary screening for secondary metabolites in micro-xylariaceous genera it was evident that they also contain several derivatives of secondary metabolites in their cultures. Even though the members of Xylariaceae studied, lack stromata, they are good source of secondary metabolite producers. Since these cultures were slow growing and the concentration of the crude extracts were comparatively lower than the stromatic Xylariaceae members, the analytical process take more time and more effort. As the final outcome, this study established a basis for the delimitation of the generic and familial boundaries of Xylariaceae and other related families and depicted a benchmark on DNA based multigene phylogeny within the Xylariaceae.
XYLARIALES FUNGI: A COMPREHENSIVE REVIEW OF THEIR DIVERSITY AND ECOLOGICAL SIGNIFICANCE
(The Library, University of Kelaniya, Sri Lanka., 2024) Jayasekera, K. A. D. H.; Daranagama, D. A. D. A.
The Xylariales fungal order is a diverse and ecologically significant group within the Ascomycota division. Primarily recognized as saprophytes, these fungi decompose and facilitate nutrient recycling. While being typically saprobic, certain Xylariales fungi exist as endophytes and can even transition to pathogens in response to environmental stresses under rare circumstances. The Xylariales order has been traditionally classified based on their distinct morphological characteristics. Still, due to recent advancements in molecular phylogeny, it has undergone extensive taxonomic revisions, leading to a more precise understanding of their classification. Among fungi, the Xylariales species are particularly prolific in producing bioactive secondary metabolites, which hold much economic importance. Renowned for its rich biodiversity, Sri Lanka harbours a potentially vast and unexplored array of Xylariales fungi. However, the full scope of the Xylariales fungal diversity and ecological significance within the country remains largely unknown. Molecular classification is crucial for accurately identifying and characterizing Xylariales fungi in Sri Lanka, enabling a deeper understanding of their ecological roles and potential applications. Further research is essential to unlock the untapped potential of these fungi in biotechnology, medicine, agriculture, and other fields.