Fungos da família Pucciniaceae na Floresta Nacional de Caxiuanã, Pará -Brasil

Abstract

The fungi of the Pucciniaceae family are classified in the order Uredinales, of the division Basidiomycota. These fungi are ecologically obligate parasites and present high specificity in relation to their hosts, constituting pathogenic organisms known as plant rust. This work aimed to identify the fungi of the Pucciniaceae family collected in the Caxiuanã National Forest, which are deposited in the MG herbarium. The identification stage considered the hosts, macroscopic observations of the symptoms caused in plants and analysis of fungal microstructures, which were observed by preparing semi-permanent slides of sera and spores, mounted in lactophenol solution and heated. We also used specialized bibliographies and comparisons with other specimens deposited in the MG herbarium. Identification keys, descriptions and illustrations of the species were made. The 106 specimens studied were identified in the genera Puccinia, with 16 species, and Uromyces, with 4 species. The identified species parasitized 12 host plant families: Asteraceae: U. wulffiae Hennings; Burseraceae: P. caxuanensis Sotão, Hennen & Rezende; Cyperaceae: P.flaoo-uirens H. S. jackson & Holway, P. minuta Dietel, P. scleriae (Pazschke) Arthur andU. sclertae P. Hennings; Heliconiaceae: P. beliconiae Arthur; Leguminosae: U. neurocarpi Dietel; Malpíghíaceae: P. insueta Winter; Malvaceae: P. heterospora Berkeley & Curtis; Marantaceae: P. tbaliae Dietel; Myrtaceae: P. psidü Winter; Poaceae: P. bambusarum Arthur, P. buberi P. Hennings and P. negrensis P. Hennings; Rhamnaceae: P paraênsis Dietel; Rubiaceae: P. borreriae P. & H. Sydow, P. lateritia Berkeley & Curtis, P.palicoureae Mains and U. holmbergii Spegazzini. The best represented host families were Cyperaceae and Rubiaceae. The species of highest occurrence were P.palicoureae (28) and P. bambusarum (21). Among the sampled ecosystems, the vegetation type Capoeira, followed by the dryland forest, were those that registered the highest frequency in relation to the number of identified species. P. beliconiae, P. flavo-virens and P. minuta are new occurrences for the State of Pará.