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Rust fungi (Uredinales) on Grewia species (Tilliaceae) in South Africa, with Uredopeltis atrides comb. nov. the new name for Ravenelia atrides
Abstract and Figures
The holdings of rust fungi on Grewia species (Tiliaceae) housed in the South African National Collection of Fungi (PREM) were examined. They belong to three morphologically
similar, but clearly separable, species of Uredopeltis, and a species of Uredo. Each rust species has a distinct and restricted host range. Ravenelia atrides is a species of Uredopeltis and is transferred accordingly. Several specimens previously accessioned under R. atrides however belong to U. chevalieri. The specimens previously accessioned under Uredo grewiae belong to U. flava, and not U. chevalieri. Three specimens are best placed in Uredo corbiculoides.
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... Specimen This is the first description of the telia (FIG. 5e, f) for this species, which are very similar to those of Uredopeltis atrides (Wood 2007), differing in being distinctly stipitate and larger. Based on morphology and hosts, there is no reason to doubt that this species belongs to Uredopeltis. ...
... Two more specimens collected in South Africa, also on G. flavescens, similarly have dimensions spanning the ranges of both these rust fungi (TABLE 2). Because the urediniospores of these specimens on G. flavescens from southern Africa consistently have a broader range of spore sizes that includes smaller ones than those of U. chevalerii (Walker and Shivas 2004;Wood 2007), and the telia are initially subepidermal becoming erumpent (FIG. 5c, d) but not as prominently erumpent as those of U. chevalerii, these specimens are referred to P. microspora. ...
... It was considered better to expand the species concept of P. microspora rather than describe another species, due to the small number of samples. So far, U. chevalerii has not yet been recorded on G. flavescens, but this plant is also a host to U. atrides (Wood 2007). Phakopsora microspora clearly belongs to the complex of Uredopeltis species on Grewia species in southern Africa (Wood 2007) and is therefore transferred to this genus. ...
... Due to changes in political borders, two species each now only occur in Mozambique (R. deformans and R. le-testui) and Zimbabwe (R. indigoferae and R. bottomleyae) respectively, while R. baumiana was recorded only from Angola. Two rusts, R. atrides and R. bottomleyae, were transferred to the genera Uredopeltis (Wood 2007) and Spumula (Thirumalachar 1946), respectively. Wood (2006) recorded R. ornata for the first time in South Africa and described R. xanthophloeae on the Vachellia xanthophloea. ...
The genus Ravenelia represents the third largest genus of rust fungi and parasitizes a great number of leguminous shrubs and trees, mainly in the subtropics and tropics. Molecular phylogenetic analyses of this genus using nc 28S rDNA and CO3 sequences are presented with a special focus on South African representatives of Ravenelia. Many of the specimens had been collected by us in recent years, mainly from acacia species of the genera Vachellia and Senegalia. Morphological characters were extensively studied using light microscopy and scanning electron microscopy. The analyses resolved several well-supported phylogenetic groups. By linking these groups to their morphology and life cycle characteristics, it was possible to interpret the outcomes in terms of their evolutionary ecology and biogeography. Several characters previously used to define subgeneric groups within Ravenelia were found to be misleading because of assumed convergent evolution. However, host associations, the ability to induce aecial galls as well as the development of two-layered probasidial cells emerged as useful criteria for inferring monophyletic groups. Six novel Ravenelia species were discovered and described. Furthermore, five species represent new reports for South Africa, species descriptions were emended for two taxa, and a new host report emerged for R. inornata.
... The specimen has been collected a number of times in the same season and also in the consecutive years but the telial stage have not been found. Previously it has been reported on Grewia latifolia Benth., G. asiatica L., G. bicolor Juss., G. breviflora Benth., G. cana Sond., G. ferruginea Hochst., G. hexamita Burret, G. monticola Sond., G. pubescens Beauv., G. salviifolia L.f. and G. tiliifolia Vahl from North Africa, South Africa, Australia and India in South Asia (Mennicken et al. 2005, Wood 2007). From Pakistan, the uredinial stage of this rust fungus has been studied on Grewia asiatica from pathological point of view (Walker and Shivas 2004). ...
... The specimen has been collected a number of times in the same season and also in the consecutive years but the telial stage have not been found. Previously it has been reported on Grewia latifolia Benth., G. asiatica L., G. bicolor Juss., G. breviflora Benth., G. cana Sond., G. ferruginea Hochst., G. hexamita Burret, G. monticola Sond., G. pubescens Beauv., G. salviifolia L.f. and G. tiliifolia Vahl from North Africa, South Africa, Australia and India in South Asia (Mennicken et al. 2005, Wood 2007). From Pakistan, the uredinial stage of this rust fungus has been studied on Grewia asiatica from pathological point of view (Walker and Shivas 2004). ...
Aecidium saussureae-affinis and Uredopeltis chevalieri are first time described and illustrated from Pakistan and are new records for this area. Grewia optiva, Carpesium trachelifolium and Malus pumila are being reported here as new host records for rust fungi. Telial stage of Phakopsora ziziphi-vulgaris is first time recorded from Pakistan and is an addition to the already reported stages of this rust. Ravenelia taslimii, Tranzschelia discolor and T. pruni-spinosae are additions to the rust flora of Khyber Pakhtunkhwa Province, Pakistan.
... A total of 49 of these recorded taxa have been recognized meanwhile to represent anamorph states or synonyms of already known species (Crous et al. 2006). Thus, about 110 species were added to the South African rust mycobiota during the last 60 years, many of them only recently (e.g., Berndt 2008bBerndt , 2010Berndt and Uhlmann 2006;Mennicken and Oberwinkler 2004;Wood 2006Wood , 2007 indicating that South Africa remains under-collected. An important aspect is that many of the described species have been collected only once or a few times and are therefore incompletely known with regard to morphological characters and variability, host range and geographical distribution. ...
This paper presents new species, combinations, national reports and host records for the South African rust fungi (Uredinales/Pucciniales).
Endophyllum mpenjatiense on cf. Hibiscus sp. (Malvaceae), Phakopsora combretorum (anamorph Uredo combreticola) on the new host Combretum apiculatum (Combretaceae) and Uredo sekhukhunensis on Ziziphus mucronata (Rhamnaceae) are described as new species. Dietelia cardiospermi and E. metalasiae are proposed as new combinations to replace Aecidium cardiospermi on Cardiospermum halicacabum (Sapindaceae) and A. metalasiae on Metalasia spp. (Asteraceae), respectively. Four species are new records for South Africa: Crossopsora antidesmae-dioicae on Antidesma venosum (Euphorbiaceae), Phakopsora ziziphi-vulgaris on Z. mucronata, and Uromyces cypericola and Puccinia subcoronata, both on a new host, Cyperus albostriatus (Cyperaceae). The record of P. subcoronata is the first one from outside the New World. Puccinia scirpi is reported as a possible addition to the South African rust fungi. New host records and observations are presented for Pucciniastrum agrimoniae that is recorded on two new host genera and species, Cliffortia odorata and Leucosidea sericea (Rosaceae), Uromyces cypericola whose urediniospores are described for the first time, Phakopsora stratosa in that spermogonia and Uredo-like aecia were discovered, and for Sphaerophragmium dalbergiae in that characters of the urediniospores are re-evaluated. A lectotype is selected for Aecidium garckeanum and spermogonia are reported for this rust for the first time. The rust fungi of Ehrharta (Poaceae) are discussed and critically evaluated in the light of spore morphology and host species.
Four new species and a new variety of rust fungi (Uredinales) are described from South Africa: Puccinia montis-venenosi on Galium spurium ssp. africanum and G. tomentosum, P. naufraga on Helichrysum sp., Uredo fynbosense on Phylica oleifolia and Ph. buxifolia, Uromyces eclipsis on Zygophyllum morgsana, and Puccinia lycii var. bizonata on Lycium sp. Puccinia austro-africana is proposed as a new combination for P. tetragoniae var. austro-africana on Tetragonia. New observations are presented about already known species: The uredinial stage of Uromyces pentaschistidis is described; Uredo monechmatis is newly reported for South Africa on new hosts and its uredinial morphology is described; a detailed description is provided
for the poorly known P. anthospermi; the identity of Uredo zygophylli, U. zygophyllina and Uromyces dinteri is discussed; a key is presented for the known Puccinia species on Helichrysum in South Africa.
Five new rust species are described and hitherto unknown spore states for the following seven species are reported: Puccinia desertorum on Evolvulus alsinoides, Uromyces comptus on Merremia bipinnatipartita, Puccinia halsei on Acacia hereroensis, Ravenelia transvaalensis on Acacia mellifera, Puccinia abutili on Abutilon angulatum, on Abutilon cf. austroafricanum, and on Abutilon cf. rehmannii, Puccinia lycii on Lycium sp. and Puccinia turgida on Lycium europaeum and on Lycium cf. oxycarpum. We also examined Uredo combreticola on Combretum cf. engleri, on Combretum hereroense, and on Combretum zeyheri, Puccinia afra on Lycium sp., and Uredopeltis cf. chevalieri on Grewia flavescens. All mentioned rust fungi are described in detail and are shown by line drawings. Selected species are illustrated with SEM-photographs.
Two species are established for the soybean rust fungi based on morphological differences between their anamorphs and teleomorphs: Phakopsora pachyrhizi includes the Austro-Asian populations whose telia are irregularly 2- to 7-spore layered, and whose teliospores have walls that are pale yellowish brown to colourless, and equally ca 1 μm thick or slightly thickened apically to 3 μm in the outermost spores. Malupa sojae (syn.: Uredo sojae) is its uredinial anamorph. Phakopsora meibomiae includes the New World populations whose telia are irregularly 1- to 4(−5)-spore layered, and whose teliospores have walls that are cinnamon- to light chestnut-brown, and 1·5–2 μm thick but thickened apically to 6 μm in the outermost spores. Malupa vignae (syn.: Uredo vignae) is its uredinial anamorph. Physopella is treated not as a teleomorph but as an anamorphic genus with connexions to Phakopsora and Cerotelium. Angiopsora is a teleomorphic genus for which Physopella was erroneously substituted. But Angiopsora is placed in synonymy under Phakopsora because its supposed defining characteristic of teliospores in vertical rows is not consistent. Malupa is named as a new anamorphic genus with sori that are surrounded by a peridium composed of one or more irregular layers of compressed and distorted hyphae ending in paraphyses. The spores are one-celled, usually echinulate, and usually sessile or almost so. The sori of Physopella are surrounded by numerous, well-defined paraphyses arising from the hymenial level, which are usually incurved over the sori. Cerotelium is separated from Phakopsora because its telial sori have a well-defined hymenium of teliosporogenous cells and hyaline, thin-walled teliospores, traits lacking in Phakopsora. In addition to two species on soybeans, four other species of Phakopsora and five species of Cerotelium parasitize legumes, each of which has either a Malupa, Milesia or Physopella anamorph. Three new unconnected Milesia species are included. All of these taxa occur on the subfamily Faboideae except two which are on Bauhinia in the Caesalpinioideae.