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Summary of morphological characters and spore sizes of Ravenelia evansii, R. macowaniana and R. xanthophloeae. All size measurements are given in μm, minimum and maximum values in parentheses. † Measurements and observations according to Doidge (1939).
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Trees in the genus Vachellia (previously Acacia ) are commonly infected by the gall-inducing rusts Raveneliamacowaniana and R.evansii . Rust galls bearing aecial infections and relating uredinial and telial infections on the leaves of nine Vachellia species not previously recorded to be infected by Ravenelia spp. have recently been collected in Sou...
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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 spec...
Trees in the genus Vachellia (previously Acacia ) are commonly infected by the gall-inducing rusts Raveneliamacowaniana and R.evansii . Rust galls bearing aecial infections and relating uredinial and telial infections on the leaves of nine Vachellia species not previously recorded to be infected by Ravenelia spp. have recently been collected in Sou...
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... A few were included in the early attempts at a phylogenetic reconstruction for Pucciniales (Wingfield et al. 2004) and Pucciniaceae (Maier et al. 2007). In addition, a few studies on specific taxa have been undertaken: a species complex of Endophyllum (Wood and Crous 2005), Macuropyxis fulva (Martin et al. 2017), Phakopsora myrtacearum (Maier et al. 2016), Puccinia on Lycieae (Ireland et al. 2019;Otálora and Berndt 2018), Solanaceae (Boshoff et al. 2022), and indigenous rye grass (Pretorius et al. 2015), Puccorchidium (Beenken and Wood 2015), Stomatisora (Wood et al. 2014), and Ravenelia (Ebinghaus et al. 2018(Ebinghaus et al. , 2020. ...
... The family concept has since been modified (Aime and McTaggart 2021), but generic limits are still problematic. Ebinghaus et al. (2018Ebinghaus et al. ( , 2020 have recently revised the taxonomy of Ravenelia species on Senegalia and Vachelia from South Africa, bringing the total number of species present in the country to 30 (15% of the described species in the genus). Two other species, both parasitic on members of the Papilionoideae, also belong to this family, namely, Diorchidium woodii and Maravalia lonchocarpi (FIG. ...
... Telia produced on the abaxial leaf surface, subepidermal in origin, erumpent, and peripherally paraphysate; paraphyses similar to aecial paraphyses. Teliospores shortpedicellate, 3e7-probasidium cells across, and 49e110 mm across, and 40e94 mm high (Fig. 2E); central probasidium cells bicellular by oblique septa (Fig. 2F), individual probasidium cells 11e33 mm high and 8e26 mm wide; the wall brown to dark reddish brown, 2e5 mm thick, ornamented with short columnar tubercles (up to 5 mm high) on central probasidium cells and long conical, apically swollen appendages (up to 20 mm long) at periphery (Fig. 2G); cysts subtending teliospores, nearly equal in number to probasidium cells, uniseriate, fused at sides, colorless, and hygroscopic (Fig. 2F, H) (Tai, 1979); on Ab. precatorius, China (Tai, 1979;Zhuang, Wei, & Wang, 2012); India (Kapoor & Agarwal, 1972;Pande & Rao, 1998;Salam & Ramachar, 1956); Nepal (Durrieu, 1980); the Philippines (Arthur & Cummins, 1936;Teodoro, 1937); Sri Lanka (Petch, 1912); Taiwan (Hiratsuka & Chen, 1991;Sawada, 1943;Zhuang, Wei, & Wang, 2012); South Africa (Wood, 2006). CommentarydRavenelia ornata was described and named based on the telial stage on Ab. pulchellus collected in Dehra Dun, India (Sydow et al., 1906). ...
... Telia produced on both leaf surfaces, subcuticular in origin, erumpent, and aparaphysate (Fig. 3D). Teliospores pedicellate, subglobose to oblong-ellipsoid in upper face view, 3e7-probasidium cells across, 33e79 mm across, and 26e63 mm high; individual probasidium cells 9e29 mm high and 7e24 mm wide (Fig. 3E); the wall apparently bilaminate, outer wall thin and yellowish brown, inner wall brown to dark brown, 2e6 mm thick, ornamented with tubercles on central probasidia and conical, apically swollen appendages at periphery (Fig. 3F and G); cysts subtending teliospores, nearly equal in number to marginal probasidium cells, uniseriate, colorless, hygroscopic ( Hosts and geographic distributiondon Ac. canescens M. Martens & Galeotti, India (Pande & Rao, 1998;Yadav, 1963); on Ac. caesia (L.) Willd., India (Tyagi & Prasad, 1978); on Ac. pennata (L.) Willd., India (Patil, Patil, & Patil, 2004); Nepal (Durrieu, 1980). ...
... Specimens examinedd on Ac. catechu (L.f.) Willd., India, Madhya Pradesh, Majhgawan, 1935, Tandon, R. N. No.192 Hosts and geographic distributiond on Ac. catechu, India (Pande & Rao, 1998;Tyagi & Prasad, 1972); Nepal (Durrieu, 1980); on Ac. nilotica (L.) Delile, Pakistan (Iqbal & Khalid, 1996). ...
Three poorly known species of Ravenelia with limited geographic distribution and one widespread species parasitizing leguminous trees (Fabaceae) were newly found in Thailand. Ravenelia odoratissimae occurred on Albizia odoratissima; R. ornata on Abrus pulchellus, Ab. precatorius, and Abrus sp.; R. parasnathii on Acacia comosa and an unidentified Acacia species; and R. tandonii on Acacia catechu. Acacia comosa is a new host for R. parasnathii. Detailed morphological study revealed that R. odoratissimae produces a uredinial stage in addition to a telial stage in its life cycle.
A new species of rust fungi Nyssopsora toonae discovered on living leaves of Toona sinensis (≡ Cedrela sinensis) from Uttarakhand, India, is described and illustrated. N. cedrelae is also reported on the same host plant, but differs from N. toonae which has a wide range of cells (1-4) and diverse teliospores shapes. Such features are not reported in any other species of the Nyssopsora. In a phylogenetic analyses based on partial 28S large subunit (LSU), 18S smaller subunit (SSU), cytochrome c-oxidase subunit 3 (CO3) and complete internal transcribed spacer (ITS) sequence data, all the Nyssopsora spp. along with N. toonae clustered together and form a separate and independent monophyletic lineage sister to Pucciniaceae in Pucciniales. The new family Nyssopsoraceae is introduced to accommodate this lineage based on the phylogenetic evidence and morphological differences from other known families. Nyssopsoraceae is characterised by its teliospores borne singly on a pedicel, with simple or branched projections all over the surface, composed of 1-4 cells (mostly 3-celled), and diverse shape. The teliospores spherical to subspherical (1-celled), dumbbell (2-celled), linearly arranged to triquetrous (3-celled), or T-shaped to tetrahedron (4-celled). A comparison of the morphological features, host plants and geographical distribution of all validly accepted species of Nyssopsora is provided.
The multicellular discoid convex teliospore heads represent a prominent generic feature of the genus Ravenelia. However, recent molecular phylogenetic work has shown that this is a convergent trait, and that this genus does not represent a natural group. In 2000, a rust fungus infecting the Caesalpinioid species Cenostigma macrophyllum (= C. gardnerianum) was described as Ravenelia cenostigmatis. This species shows some rare features, such as an extra layer of sterile cells between the cysts and the fertile teliospores, spirally ornamented urediniospores, as well as strongly incurved paraphyses giving the telia and uredinia a basket-like appearance. Using freshly collected specimens of Rav. cenostigmatis and Rav. spiralis on C. macrophyllum, our phylogenetic analyses based on the nuc 28S, nuc 18S, and mt CO3 (cytochrome c oxidase subunit 3) gene sequences demonstrated that these two rust fungi belong in a lineage within the Raveneliineae that is distinct from Ravenelia s. str. Besides proposing their recombination into the new genus Raveneliopsis (type species R. cenostigmatis) and briefly discussing their potentially close phylogenetic affiliations, we suggest that five other Ravenelia species that are morphologically and ecologically close to the type species of Raveneliopsis, i.e., Rav. corbula, Rav. corbuloides, Rav. parahybana, Rav. pileolarioides, and Rav. Striatiformis, may be recombined pending new collections and confirmation through molecular phylogenetic analyses.
The genus Cerradoa (type species Cerradoa palmaea) was established in 1978 by Hennen and Ono and named after the Brazilian Cerrado biome. The holotype collected in Planaltina, Federal District, Brazil, belonged to the first rust fungus reported on palms (Arecaceae). For decades, the status of Cerradoa as a distinct genus has been regarded as doubtful, representing a synonym of Edythea (Uropyxidaceae) starting with the second edition of the Illustrated Genera of Rust Fungi in 1983. Our molecular phylogenetic analyses, as well as our morphological investigations, allowed us to reject this synonymy, leading to the reinstatement of Cerradoa within the Pucciniaceae. Cerradoa, together with morphologically similar genera such as the newly established Pseudocerradoa with two species (Ps. paullula and Ps. rhaphidophorae) infecting araceous hosts, the fern rust Desmella, and also P. engleriana, could not be assigned to any of the seven identified major lineages within the Pucciniaceae. Edythea, instead of being maintained as a member of the Uropyxidaceae, was herein placed in Pucciniaceae, shown phylogenetically in close relationship to Cumminsiella mirabilissima, both infecting the Berberidaceae. Additionally, our extensive phylogenetic analyses add guidance for future taxonomic revisions in the highly polyphyletic genus Puccinia and other established taxa within the family Pucciniaceae.
Fungi are eukaryotes that play essential roles in ecosystems. Among fungi, Basidiomycota is one of the major phyla with more than 40,000 described species. We review species diversity of Basidiomycota from five groups with different lifestyles or habitats: saprobic in grass/forest litter, wood-decaying, yeast-like, ectomycorrhizal, and plant parasitic. Case studies of Agaricus, Cantharellus, Ganoderma, Gyroporus, Russula, Tricholoma, and groups of lichenicolous yeast-like fungi, rust fungi, and smut fungi are used to determine trends in discovery of biodiversity. In each case study, the number of new species published during 2009–2020 is analysed to determine the rate of discovery. Publication rates differ between taxa and reflect different states of progress for species discovery in different genera. The results showed that lichenicolous yeast-like taxa had the highest publication rate for new species in the past two decades, and it is likely this trend will continue in the next decade. The species discovery rate of plant parasitic basidiomycetes was low in the past ten years, and remained constant in the past 50 years. We also found that the establishment of comprehensive and robust taxonomic systems based on a joint global initiative by mycologists could promote and standardize the recognition of taxa. We estimated that more than 54,000 species of Basidiomycota will be discovered by 2030, and estimate a total of 1.4–4.2 million species of Basidiomycota globally. These numbers illustrate a huge gap between the described and yet unknown diversity in Basidiomycota.
Species delimitation is one of the most fundamental processes in biology. Biodiversity undertakings, for instance, require explicit species concepts and criteria for species delimitation in order to be relevant and translatable. However, a perfect species concept does not exist for Fungi. Here, we review the species concepts commonly used in Basidiomycota, the second largest phylum of Fungi that contains some of the best known species of mushrooms, rusts, smuts, and jelly fungi. In general, best practice is to delimitate species, publish new taxa, and conduct taxonomic revisions based on as many independent lines of evidence as possible, that is, by applying a so-called unifying (or integrative) conceptual framework. However, the types of data used vary considerably from group to group. For this reason we discuss the different classes of Basidiomycota, and for each provide: (i) a general introduction with difficulties faced in species recognition, (ii) species concepts and methods for species delimitation, and (iii) community recommendations and conclusions.
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 Basidiomycota constitutes a major phylum of the kingdom Fungi and is second in species numbers to the Ascomycota. The present work provides an overview of all validly published, currently used basidiomycete genera to date in a single document. An outline of all genera of Basidiomycota is provided, which includes 1928 currently used genera names, with 1263 synonyms, which are distributed in 241 families, 68 orders, 18 classes and four subphyla. We provide brief notes for each accepted genus including information on classification, number of accepted species, type species, life mode, habitat, distribution, and sequence information. Furthermore, three phylogenetic analyses with combined LSU, SSU, 5.8s, rpb1, rpb2, and ef1 datasets for the subphyla Agaricomycotina, Pucciniomycotina and Ustilaginomycotina are conducted, respectively. Divergence time estimates are provided to the family level with 632 species from 62 orders, 168 families and 605 genera. Our study indicates that the divergence times of the subphyla in Basidiomycota are 406–430 Mya, classes are 211–383 Mya, and orders are 99–323 Mya, which are largely consistent with previous studies. In this study, all phylogenetically supported families were dated, with the families of Agaricomycotina diverging from 27–178 Mya, Pucciniomycotina from 85–222 Mya, and Ustilaginomycotina from 79–177 Mya. Divergence times as additional criterion in ranking provide additional evidence to resolve taxonomic problems in the Basidiomycota taxonomic system, and also provide a better understanding of their phylogeny and evolution.
