Search

This study revises Uromyces(Pucciniales or Uredinales) on the economically important plant family Cucurbitaceae and presents descriptions, illustrations and a key to aid determination of the 17 recognized species and four varieties. Seven species are described as new: Uromyces aimeae, U. aquiriensis, U. cucumivorus, U. infarctus, U. naucinus, U. saulensisand U. superstomatalis. Uromyces novissimusoccurs on a number of tribes of Cucurbitaceae and is broadly circumscribed as a variable species that comprises four varieties. Variety cissampelidis, var. hellerianusand var. pentastriatus, are new combinations for U. cissampelidis, U. hellerianusand U. pentastriatusthat have been regarded so far either as synonyms of U. novissimusor distinct species. The new name U. ernesti-uleiis proposed to replace the illegitimate name U. cayaponiaethat refers to a uredinial state. It has been synonymized with U. novissimusas well but is considered a distinct species. Uromyces reynoldsiiis reduced to a synonym of U. yakushimensisand a lectotype is selected for U. guraniae. Uromyces aimeae, U. neotropicalisand U. superstomatalisdiffer from the remaining species in superstomatal uredinia and telia and appear to be the first Uromycesspp. in which such sori are reported. The chytrid Olpidium uredinisis reported from three species, U. ernesti-ulei, U. guraniaeand U. novissimusvar. hellerianus, which are new hosts of this mycoparasite.

Dasyspora gregaria, the single species of the allegedly monotypic rust genus Dasyspora(Basidiomycota, Pucciniales), was investigated by light microscopy and DNA sequencing (ITS1–5.8S–ITS2 region, partial LSU and SSU of the nuclear rDNA, mt cytochrome oxidase subunit 3). Both methods indicated that D. gregariais not a single species but can be split in 11 distinct taxa, each of which appear confined to a single Xylopiaspecies (Annonaceae) host. Herein nine of these are described as new. Both the phylogenetic analyses and morphology show that the species are grouped into two main clades designated Dasyspora gregariaand D. winteri. The first comprises D. gregaria, the type species of the genus, which is restricted to X. cayennensis,two new species on X. aromatica, D. segregariafrom northern South America and D. echinatafrom Brazil. The second clade is formed by D. winteri, recombined from Puccinia winterion X. sericea,and the new species D. amazonicaon X. amazonica, D. emarginataeon X. emarginata, D. frutescentison X. frutescens, D. ferrugineaeon X. frutescensvar. ferruginea, D. guianensison X. benthamii, D. mesoamericanaon X. frutescens, and D. nitidaeon X. nitida. Dasyspora frutescentisand D. mesoamericanawere not clearly distinguishable by their morphology and host associations but differed from another in their sequences and geographic distributions. They are considered cryptic species. An identification key and the distributions are given for all recognized species. Along with molecular data we discuss the systematic position of Dasysporain the Pucciniales.

Pucciniaspecies (rust fungi, Pucciniales, formerly Uredinales) occurring on Berkheya(syn. Stobaea) of Asteraceae are critically evaluated. Puccinia berkheyicola, P. stobaeaevar. stobaeaeand P. stobaeaevar. woodiiare recognized as valid species and varieties, while P. berkheyaeis relegated to a synonym of P. stobaeaevar. stobaeae. Lectotypes are selected for P. stobaeaevar. stobaeaeand P. stobaeaevar. woodii. P. clanwilliamensis, P. garstfonteiniiand P. monsfontiumare proposed as new species for three rust fungi previously assigned to P. stobaeae; P. berkheyaephilais described as new on B. bipinnatifida. A key to the accepted species is presented.

AbstractGoplana ribis-andicolae, Puccinia ponsae, P. promatensis, Uromyces siphocampyli-gigantei, Uredo cyclanthacearum, U. merremiae, and U. semidisciferaare described as new species. The ultrastructure of the urediniospore ornament of Uredo semidisciferawas studied. Uredo floridanarevealed a one-layered pseudoparenchymatous uredinial peridium and D-haustoria with necks wrapped by a fold of the extrahaustorial membrane. It is therefore assigned to Melampsoraceae and probably belongs to the genus Pucciniastrum. Uredo polylepidishad a similar uredinial peridium and may belong also to the genus Pucciniastrum.

Six new species of Puccinia on Baccharis are described: Puccinia basirostrata, P. ecuadorientalis, P. lentapiculata, P. otavalensis and P. quitensis from Ecuador, and P. vulcanicola from Costa Rica. Beside features of telio-, uredinio- and aeciospores, basidiospore morphology yielded important characters for species delimitation.

A new rust fungus on Dioscorea, Cerotelium dioscoreae, sp. nov. is described from Ecuador. Similarity with other phakopsoraceous genera and the assignment of the new fungus to Cerotelium is discussed.

AbstractNew species of rust fungi (Uredinales) are described from Ecuador and Venezuela: Prospodium manabiion Bignoniaceae, Puccinia garcilassaeon Garcilassa rivularis, Pu. machalillaeon Wedeliacf. grandiflora, Uromyces valerianae-microphyllaeon Valeriana microphylla, Uredo verruculosaon Pteridium aquilinum, U. ribesii-andicolaeon Ribescf. andicola, and Aecidium begoniaeon Begoniasp. Uromyces valerianae-microphyllaeappears to be the perfect state of Uredo quitensis. Uredo verruculosaprobably belongs to a Uredinopsissp.

AbstractThe morphology and ultrastructure of dikaryotic haustoria (D-haustoria) of Melampsorella caryophyllacearumand Melampsorella symphyti(Uredinales, Pucciniastraceae) were found to be different. The haustorium of M. caryophyllacearumwas branched apically and the haustorial neck was sheathed by a fold of the extrahaustorial membrane. A system of filamentous structures was present in the matrix fold around the neck. In M. symphyti, no such matrix fold was present and the haustorial body was unbranched. D-haustoria of Thekopsora areolatawere bulbous and unbranched. They differed from D-haustoria of other Thekopsoraspecies by the presence of a matrix fold at the haustorial neck. Melampsorella, Thekopsoraand Pucciniastrumare the only pucciniastraceous genera, so far that revealed different haustorial types. The systematic implications are discussed.

The ultrastructure of dikaryotic haustoria of seven Pucciniastrumspecies. Thekopsora galii, Naohidemyces vaccinii, and Calyptospora goeppertianawas investigated. Pucciniastrum actinidiae, P. agrimoniae, P. pyrolae, and Calyptospora goeppertianarevealed haustoria whose necks were wrapped by a fold of the extrahaustorial matrix. The matrix-fold of Calyptospora goeppertianawas characteristically shaped. Pucciniastrum circaeae, P. epilobii, P. hikosanense, P. styracinum. Thekopsora galii, and Naohidemyces vacciniishowed typical haustorial necks which were not sheathed by a matrix-fold. Haustorial necks which were wrapped by a fold of the extrahaustorial matrix were designated “velopedunculate.” and those which were naked “gymnopedunculate.” The application of haustorial ultrastructure as a character for use in systematics is discussed.

The haustorial morphology of 21 Ravenelia species, two Kernkampella species, and four leguminicolous Uredo and Uraecium species which are probably related to Ravenelia, was investigated by light microscopy. Three different kinds of interaction could be found: (1) species with haustorial complexes comprising dikaryotic haustoria and intracellular hyphae. These species showed strictly intracellular growth of the parasitic mycelium. (2) Species with only dikaryotic haustoria, and (3) species with only intracellular hyphae or monokaryotic haustoria. Complexes of dikaryotic haustoria and intracellular hyphae were found in 17 of the investigated Ravenelia species and three Uredo species. Three Ravenelia species revealed dikaryotic haustoria, and Ravenelia lonchocarpicola had only intracellular hyphae. Complexes of dikaryotic haustoria and intracellular hyphae are probably the prevalent type of parasitic interaction in Ravenelia. The investigated Kernkampella species revealed dikaryotic haustoria.