Sistemática filogenética de Lactifluus (Russulales) com ênfase em espécies do Norte e Nordeste brasileiro

Abstract

Lactifluus (Rusulaceae, Rusulales) comprises fungi that produce in their reproductive form agaricoid, pleurotoid and gasteroid basidiomata; mainly characterized by latex exudation. The genus has approximately 210 species distributed mostly in the tropics, where they frequently form ectomycorrhizal association with a wide variety of plants. The diversity of the genus has been better investigated in Africa and Asia, while remains underexplored in Neotropical region. In Brazil, only nine Lactifluus species were described or reported from Amazon, Atlantic Forest and Caatinga, and another ten species still treated as Lactarius needed to be revised and confirmed. Thus, the proposed project aimed to systematize and interpret the genus Lactifluus from morphological and molecular analysis, with the increase of new collections and review of collection of Herbaria from different biomes in the North and Northeast regions of Brazil. The analyzes were based on morphological and molecular data from ten specimens deposited in the PACA, INPA, JPB UFRN-Fungos and URM Herbaria; and also from additional 31 specimens collected in different ecosystems of Amazonia, Caatinga and Atlantic Forest. The morphological review of herborized collections resulted in recombination of Lactifluus amazonensis, Lf. brasiliensis, Lf. braunii, Lf. mamorensis, Lf. russula and Lf. rupestris; and in the designation of one lectotype for Lf. annulifer, Lf. braunii and Lf. russula. New sample resulted in the identification and sequencing of Lf. amazonensis, Lf. annulifer, Lf. dunensis, Lf. lepus, Lf. neotropicus and Lf. mamorensis. Another 11 species were proposed as new to science: Lf. aurantioceraceus nom. prov., Lf. brunneoruber nom. prov., Lf. candidus nom. prov., Lf. flavuscaespitosus nom. prov., Lf. guttulatus sp. nov., Lf. perforatus nom. prov., Lf. piperogalactus sp. nov., Lf. reniformis nom. prov., Lf. restingae nom. prov., Lf. sphatuliformis sp. nov. and Lf. umbilicatus sp. nov. Molecular analysis of the ITS, LSU and RPB2 DNA regions of the collected specimens confirm the distinct lineages of the cited species in Lactifluus, in which are distributed in five different clades in the subgenera Gymnocarpi, Lactariopsis and Pseudogymnocarpi. Furthermore, the phylogenetic analyses of the collected specimens provided support for delimitation of two sections: Lf. section Piperogalacti sect. nov. and Lf. section Multicepis nom prov.; and emendation of Lf. sect. Panuoidei.