Systematic studies on the boletoid fungi (Agaricomycetes, Basidiomycota) of Kerala

Abstract

Boletoid fungi are a monophyletic group (Boletales Agaricomycetes, Basidiomycota) with members producing basidiomata that are usually fleshy, stipitate-pileate and with poroid or lamellate hymenophore. Most of the species form ectomycorrhizal associations with higher plants. Many are edible. Boletoid fungi have been studied in detail from around the world. In India, boletoid fungi have been fairly documented from northern states. However, there are no comprehensive studies on the Boletales of South India. Hence, a documentary study of the boletoid fungi of Kerala was conducted during the period 2018-2024. Morphological characterisation along with molecular phylogenetic analyses of the collected specimens were conducted. Boletoid specimens were collected from different parts of Kerala State. Molecular characterization of collected specimens were done using various gene regions (ITS, 28S and RPB2). Phylogenetic trees were generated by using Maximum Likelihood method. A total of 185 boletoid taxa were collected during the five-year period. Significant number of bolete collections were obtained from Kuruva Islets and the Thurayilkotta Sacred grove. Forty bolete species belonging to 29 genera of eight families (Boletaceae, Boletinellaceae, Gyroporaceae, Paxillaceae, Pisolithaceae, Serpulaceae, Sclerodermataceae, Suillaceae) were recorded. Fourteen species were found to be hitherto undescribed. Five species were formally published and other undescribed species are in the process of publication. A collection was found to belong to a genus new to science. Out of the total taxa documented, nine were new records to India and 18 were new records to Kerala. All the specimens, including holotypes are maintained at Zamorin’s Guruvayurappan College Herbarium (ZGC). A total of 50 gene sequences were generated from the collections during the study and were used for molecular phylogenetic analyses. Newly generated gene sequences were deposited in open repository. This taxonomic treatment provides descriptions, comparisons, taxonomic keys and molecular phylogenetic analyses of boletes along with macroscopic and microscopic photographs.