Diversity and phylogeny of basidiomycetous yeasts from plant leaves and soil: Proposal of two new orders, three new families, eight new genera and one hundred and seven new species.

Nearly 500 basidiomycetous yeast species were accepted in the latest edition of The Yeasts: A Taxonomic Study published in 2011. However, this number presents only the tip of the iceberg of yeast species diversity in nature. Possibly more than 99 % of yeast species, as is true for many groups of fungi, are yet unknown and await discovery. Over the past two decades nearly 200 unidentified isolates were obtained during a series of environmental surveys of yeasts in phyllosphere and soils, mainly from China. Among these isolates, 107 new species were identified based on the phylogenetic analyses of nuclear ribosomal DNA (rDNA) [D1/D2 domains of the large subunit (LSU), the small subunit (SSU), and the internal transcribed spacer region including the 5.8S rDNA (ITS)] and protein-coding genes [both subunits of DNA polymerase II (RPB1 and RPB2), the translation elongation factor 1-α (TEF1) and the mitochondrial gene cytochrome b (CYTB)], and physiological comparisons. Forty-six of these belong to 16 genera in the Tremellomycetes (Agaricomycotina). The other 61 are distributed in 26 genera in the Pucciniomycotina. Here we circumscribe eight new genera, three new families and two new orders based on the multi-locus phylogenetic analyses combined with the clustering optimisation analysis and the predicted similarity thresholds for yeasts and filamentous fungal delimitation at genus and higher ranks. Additionally, as a result of these analyses, three new combinations are proposed and 66 taxa are validated.

Deconstructing the evolutionary complexity between rust fungi (Pucciniales) and their plant hosts.

The rust fungi (Pucciniales) are the most speciose natural group of plant pathogens, members of which possess the most complex lifecycles in Fungi. How natural selection works on the Pucciniales has been the subject of several hypotheses in mycology. This study uses molecular age estimation using sequence data from multiple loci, and cophylogeny reconciliation analyses to test hypotheses regarding how the aecial and telial stages in the lifecycle of rust fungi may have differentially impacted their diversification. Molecular age estimates show that the timing of diversification in the Pucciniales correlates with the diversification of their gymnosperm and angiosperm hosts. Host reconciliation analyses suggest that systematic relationships of hosts from the aecial stage of the Pucciniales lifecycle better reflect the systematic relationships among the Pucciniales. The results demonstrate the relative importance of this stage on the overall evolution of the Pucciniales and supports hypotheses made by Leppik over half a century ago. This study represents the first evaluation of how different life stages in the Pucciniales shape the evolution of these fungi.

The cacao pathogen Moniliophthora roreri (Marasmiaceae) possesses biallelic A and B mating loci but reproduces clonally.

The cacao pathogen Moniliophthora roreri belongs to the mushroom-forming family Marasmiaceae, but it has never been observed to produce a fruiting body, which calls to question its capacity for sexual reproduction. In this study, we identified potential A (HD1 and HD2) and B (pheromone precursors and pheromone receptors) mating genes in M. roreri. A PCR-based method was subsequently devised to determine the mating type for a set of 47 isolates from across the geographic range of the fungus. We developed and generated an 11-marker microsatellite set and conducted association and linkage disequilibrium (standardized index of association, IA(s)) analyses. We also performed an ancestral reconstruction analysis to show that the ancestor of M. roreri is predicted to be heterothallic and tetrapolar, which together with sliding window analyses support that the A and B mating loci are likely unlinked and follow a tetrapolar organization within the genome. The A locus is composed of a pair of HD1 and HD2 genes, whereas the B locus consists of a paired pheromone precursor, Mr_Ph4, and receptor, STE3_Mr4. Two A and B alleles but only two mating types were identified. Association analyses divided isolates into two well-defined genetically distinct groups that correlate with their mating type; IA(s) values show high linkage disequilibrium as is expected in clonal reproduction. Interestingly, both mating types were found in South American isolates but only one mating type was found in Central American isolates, supporting a prior hypothesis of clonal dissemination throughout Central America after a single or very few introductions of the fungus from South America.

A co-evolutionary relationship exists between Endoraecium (Pucciniales) and its Acacia hosts in Australia.

Endoraecium is a genus of rust fungi that infects several species of Acacia in Australia, South-East Asia and Hawaii. This study investigated the systematics of Endoraecium from 55 specimens in Australia based on a combined morphological and molecular approach. Phylogenetic analyses were conducted on partitioned datasets of loci from ribosomal and mitochondrial DNA. The recovered molecular phylogeny supported a recently published taxonomy based on morphology and host range that divided Endoraecium digitatum into five species. Spore morphology is synapomorphic and there is evidence Endoraecium co-evolved with its Acacia hosts. The broad host ranges of E. digitatum, E. parvum, E. phyllodiorum and E. violae-faustiae are revised in light of this study, and nine new species of Endoraecium are described from Australia based on host taxonomy, morphology and phylogenetic concordance.

The Rose Rust Fungus, Phragmidium tuberculatum, is Widespread in the Americas: First Reports from California, Oregon, Massachusetts, and Honduras.

The rust fungus Phragmidium tuberculatum Jul. Müll. is a common pathogen on Rosa spp., on which all life cycle stages are formed. Symptoms occur in spring and may include distorted stems, yellow spots on the upper leaf surface, and a bright orange spore mass formed on the abaxial leaf surface. In late summer, sori become speckled with black as fascicles of teliospores develop. The current known distribution of P. tuberculatum is mostly limited to Europe with some occurrence in Asia and into Australasia (2). There is some documented occurrence in North America (Alaska, Connecticut, and Canada [2]), where most rose rust disease is attributed to P. mucronatum (Pers.) Schltdl. This study used a combination of molecular and morphological analyses on newly collected material from across North America (California: BPI877978, PURN7783; Oregon: BPI877980; Massachusetts: BPI877977; and Quebec: BPI877979) and herbarium material from South and Central America (Honduras: BPI864186; and Argentina: BPI843677; both previously identified as P. mucronatum) to document a much broader distribution of P. tuberculatum. Collectively, teliospores from these collections are 4 to 6 celled, dark to black-brown, warted, elongated to cylindrical, 64.7 to 92.4 µm in length by 23.1 to 39.3 µm in width (average 77.6 × 30.0 µm) (30 teliospores from 2 leaves), with 2 to 3 pores/cell and a pronounced hyaline apiculus 4.6 to 18.5 µm long (average 8.3 µm). P. tuberculatum is similar morphologically to P. mucronatum, but sensu Gäumann (3) differs in having wider (30 to 36 µm) and longer (65 to 110 µm) teliospores with an average of 6 to 8 cells/spore. However, the two are easily distinguished by DNA analyses (4). The 28S sequences were amplified using the protocols described in Aime (1) and compared phylogenetically to 28S sequences available in the GenBank database for P. tuberculatum, P. mucronatum, and other Phragmidium spp. (4). In a maximum likelihood analysis, all isolates formed a 99% bootstrap supported clade with P. tuberculatum sequences from Germany, and shared 100% sequence identity with JF907675 P. tuberculatum. In contrast, comparison with HQ421646 P. mucronatum produced only 92% identity (e.g., 836/911 bp for PURN7783). This information indicates that P. tuberculatum is likely to be widespread in the Americas but simply misidentified as P. mucronatum, as was found to be the case for the two herbarium specimens sampled. Detailed examination of historical herbarium material may help to pinpoint how long the fungus has been present and the current extent of its distribution. The rose rust fungus is not considered to be a problem economically, but its spread within North America may be an indicator of commercial practices that serve as a vector for other diseases on ornamental plants. Voucher specimens have been deposited in the U.S. National Fungus Collections (BPI) and Arthur Fungarium (PUR); voucher sequences are deposited in GenBank (Accession Nos. KJ841917 to 23). References: (1) M. C. Aime. Mycoscience 47:112, 2006. (2) J. F. Arthur. Manual of the rusts in United States and Canada. Purdue Research Foundation, 1934. (3) E. Gäumann. Die Rostpilze Mitteleuropas mit besonderer Berücksichtigung der Schweiz. Büchler, Bern, 1959. (4) C. M. Ritz et al. Mycol. Res. 109:603, 2005.

First Report of the White Pine Blister Rust Fungus, Cronartium ribicola, on Ribes odoratum in Indiana.

Cronartium ribicola J. C. Fisch., causal agent of white pine blister rust (WPBR), is one of the most damaging pathogens of five-needle pines, forming aecial states on the trunk and branches and causing cankering, topkill, and branch dieback. Infection can predispose hosts to attack by other pests such as bark beetles, and can result in host mortality. Various species of Ribes, Pedicularis, and Castilleja are alternate hosts on which C. ribicola forms its uredinial and telial states during the mid-summer to fall. In an effort to mitigate the damage caused by white pine blister rust, the planting of ornamental species of Ribes, such as R. occidentalis, is prohibited in 14 states. Indiana currently has no restrictions on the planting of Ribes spp. Since 2010, a Cronartium sp. has been observed producing uredinia and telia on R. odoratum 'Crandall' H.L. Wendl. leaves in an urban environment in West Lafayette, Indiana. Symptoms include yellow-orange lesions on the leaf upper surface with uredinia on the underside. These persist from late summer until leaf drop. Telia were collected in 2011 to establish the identity of the causal agent using morphological and molecular analyses. Morphological comparisons between this specimen and other Cronartium species were made using Arthur (2). Filiform telial columns ranged from 0.5 to 1.5 mm in length. Teliospores were cylindrical to sub-ventricose, truncate on either end with one end generally tapering more than the other, and measured 9.0 to 18.6 × 37.2 to 60.0 µm (average 11.9 × 47.4 µm from 30 spores across 4 leaves). These teliospore measurements overlap those of C. ribicola and C. occidentale, but are more consistent with C. ribicola, in which the spores are wider and longer (8 to 12 × 30 to 60 µm) than in C. occidentale (9 to 10 × 27 to 56 µm). For molecular analyses, two nuclear ribosomal loci were sequenced: the internal transcribed spacer regions 1, 2, and 5.8S (ITS) and the 5' end of the large subunit (28S) (1). The ITS sequence was 665 bp long (KF387533) and the 28S was 892 bp (KC876675). These sequences were queried to GenBank using a BLASTn search. The 28S shared 99% identity (891/892 bp) and the ITS shared 100% identity (663/663 bp) to other published C. ribicola sequences with no close matches to any other species with either locus. Both morphological and molecular methods indicate this species to be C ribicola, making this a first report of white pine blister rust on R. odoratum in Indiana. This fungus has been observed previously on R. odoratum in the northeastern United States (Connecticut, Massachusetts, Rhode Island, Vermont, and New Hampshire), the Rockies (Colorado), northwestern United States (Washington), and Canada (3). In Indiana, C. ribicola has also been reported on R. cysnobati. There are no other reports of this fungus on any other host within the state. However, the aecial host, Pinus strobus, does grow within the state, and within West Lafayette. To our knowledge, WPBR has only been observed (not reported) once in Indiana in the past 30 years (Paul Pecknold, personal communication). Further monitoring of C. ribicola hosts is needed in Indiana to determine the extent of the disease. The specimen has been vouchered in the Arthur Herbarium (PUR N6734). References: (1) M. C. Aime. Mycoscience 47:112. 2006. (2) J. F. Arthur. Manual of the Rusts in United States and Canada. Purdue Research Foundation, 1934. (3) D. F. Farr and A. Y. Rossman. Fungal Databases Systematic Mycology and Microbiology Laboratory, ARS, USDA. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ April 23, 2013.

First Report of Rust Caused by Puccinia nakanishikii on Lemongrass, Cymbopogon citratus, in Florida.

Lemongrass, Cymbopogon citratus (DC.) Stapf. (Poaceae), is grown widely in the tropics and subtropics as an ornamental, flavoring ingredient in Asian cooking, and for tea and fragrant oil (3). In February 2013, rust symptoms were observed on lemongrass in several gardens in Miami-Dade County, Florida. Symptoms began as small chlorotic flecks on both leaf surfaces that became crimson and enlarged to streaks ~1 cm in length. On the abaxial side of leaves, erumpent streaks ruptured to produce pustules in which urediniospores formed. Eventually, streaks coalesced to produce large patches of tan to purplish necrotic tissue that blighted most of the leaf surface and was often surrounded by chlorotic borders. These symptoms, fungal morphology, and nuclear ribosomal large subunit (28S) DNA analysis were used to identify the pathogen as Puccinia nakanishikii Dietel. Urediniospores were pyriform to globose, orange to crimson, slightly echinulate, and somewhat longer than a previous report (32.1 ± 3.4 (27 to 42) × 23.3 ± 2.4 (21 to 27) µm vs. 22 to 28 × 22 to 25 µm) (2). Uredinia contained clavate paraphyses, but teliospores were not observed. No aecial host is known for this pathogen. A 28S DNA sequence that was generated with the NL1 and LR3 primers (1,4) was deposited in GenBank under accession no. KC990123; it shared 99% identity with GenBank accession GU058002, which came from a specimen of P. nakanishikii in Hawaii. Voucher specimens of affected leaves of lemongrass have been deposited at the Arthur Herbarium, Purdue University. Although this disease has been reported in California, Hawaii, New Zealand, and Thailand, this is believed to be the first report from Florida (2). Based on rainfall and temperature conditions that are conducive to its development in South Florida, it has the potential to significantly reduce the health and production of this plant in area gardens. References: (1) C. P. Kurtzman and C. J. Robnett. Antonie Van Leeuwenhoek 73:331. 1998. (2) S. Nelson. Rust of Lemongrass. Univ. Hawaii PD-57, 2008. (3) USDA, ARS, GRIN Online Database. URL: http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?12797 , accessed 25 April 2013. (4) R. Vilgalys and M. Hester. J Bacteriol. 172:4238, 1990.

First Report of Orange Rust of Sugarcane Caused by Puccinia kuehnii in Ecuador.

Orange rust, Puccinia kuehnii (W. Krüger) E.J. Butler, is an important disease of sugarcane (complex hybrid of Saccharum L. species) that causes up to 53% yield loss (3), and can eliminate sugarcane clones in breeding programs. Initially confined to the Asia-Oceania region, P. kuehnii was reported in Florida in June 2007 (2) followed by confirmation in Central and South America. Orange rust pustules were observed on August 5, 2011, in commercial sugarcane fields located in the Ecuadorian Pacific coast of South America. Pustules were observed on cultivar SP79-2233 and sugarcane clones of the CINCAE breeding program (EC06-351, EC06-340, and EC01-744). Low levels of disease incidence and severity were observed in the sugarcane germplasm. Observation under a light microscope showed typical irregularly echinulate urediniospores that were pale in color with thickened apices and paraphyses inconspicuous to absent, such as those reported to be P. kuehnii (4). DNA of urediniospores were extracted and amplified using Pk1F and PK1R qPCR primers (5). Additionally, the 28s large ribosomal subunit DNA was sequenced (1), resulting in a qPCR and 100% sequence identity with a partial sequence of the P. kuehnii 28S ribosomal RNA gene, accession GU058010 (932/932 base pairs, GenBank Accession No. KF202306). Based on urediniospore morphology, DNA amplification, and sequence analysis, the causal agent of the rust observed in Ecuador was confirmed to be P. kuehnii. Commercial varieties have not yet shown symptoms of infections. However, a survey conducted in 2011 and 2012 showed an increase of disease severity from 3% to 28% in the susceptible cv. SP79-2233. Disease symptoms were evident from stalk growth to maturity (7 to 12 months), especially at the beginning of the harvesting season. To our knowledge, this is the first report of the presence, distribution, and disease spread by the sugarcane orange rust pathogen P. kuehnii in Ecuador. References: (1) M. C. Aime. Mycoscience 47:112, 2006. (2) J. C. Comstock et al. Plant Dis. 92:175, 2008. (3) J. C. Comstock et al. ASSCT. 29:82, 2009. (4) L. Dixon and L. Castlebury. Orange Rust of Sugarcane - Puccinia kuehnii. Syst. Mycol. Microbiol. Lab. Retrieved from /sbmlweb/fungi/index.cfm, August 12, 2011. (5) N. C. Glynn et al. Plant Pathol. 59:703, 2010.

First Report of Uromyces plumbarius, Rust of Gaura, in Louisiana and a new host, Guara lindheimeri.

Gaura lindheimeri Engelm. & A. Gray (Onagraceae) is an ornamental shrub that is native to southern Louisiana and Texas. Its texture and form make it a popular perennial border plant. In April 2010 and 2011, three collections of Guara leaf samples with signs and symptoms of a rust disease were made from a home garden in Baton Rouge, LA. Infected leaves showed chlorotic lesions on the adaxial surface and were associated with scattered, hypophyllous uredinia. Urediniospores were globose to obovoid, echinulate, had two equatorial germ pores, and measured 16 to 21 × 18 to 25 µm with a wall 2 µm thick. Telia and teliospores were not observed on any of the collected samples. The pathogen was identified as Uromyces plumbarius Peck on the basis of the uredinial characters compared with four U.S. National Fungus (BPI 1103868, 0013551, 0013554, and 0013557) collections of U. plumbarius. The three collections from Louisiana have been deposited in the Bernard Lowy Mycological Herbarium. DNA was extracted from all three specimens and the nuclear ribosomal large subunit (28S) was amplified according to the protocol outlined by Aime (1). The three Louisiana collections had identical large subunit sequences (GenBank Accession Nos. JQ312670, JQ312671, and JQ312672). No sequences of U. plumbarius were available for comparison in GenBank; a BLAST search was 99% similar over 100% query coverage to Puccinia dioicae Magnus (Accession No. GU058019) and P. silvatica J. Schröt. (Accession No. AY222048). The uredinial/telial hosts of P. dioicae and P. silvatica are in the Cyperaceae, whereas U. plumbarius is an autoecious rust on Onagraceae. It is interesting to note that the aecial stage of P. dioicae occurs on Onagraceae and that it has a high sequence identity to U. plumbarius, supporting the hypothesis that these are correlated species (2). U. plumbarius has been recorded on several species of Gaura within the United States. To our knowledge, this is the first record of U. plumbarius in Louisiana and the first report of U. plumbarius on G. lindheimeri. References: (1) M. C. Aime. Mycoscience 47:112, 2006. (2) C. R. Orton. Mycologia 4:194, 1912.

First Report of Puccinia thaliae Rust on Canna Lily in Louisiana.

Canna lily is a monocot, herbaceous perennial ornamental plant in the Cannaceae that is native to tropical South America and cultivated throughout the southern United States. Canna lily is a popular garden and landscaping plant and a large horticultural industry depends on this plant. In September 2008 and again in November 2009, two species of Canna lily (Canna × generalis L.H. Bailey and C. indica L.) were found to be severely infected with rust disease in three garden locations in southern Louisiana (East Baton Rouge Parish, Lafayette Parish, and Orleans Parish). Diseased samples from both host species and all locations exhibited similar symptoms of numerous, yellowish brown, subepidermal, erumpent, and irregular-shaped uredinia on both leaf surfaces. Initially, sori were scattered, later covering the entire leaf with coalescing pustules. Urediniospores were subglobose to ovoid or pyriform, echinulate, and measured 25.74 to 37.18 (-38.61) × 17.16 to 27.17 (-28.6) µm, with thickened apical walls, 1.3 to 1.6 µm, and one to two equatorial germ pores. Telia and teliospores were not observed on any of the collected samples. Pathogen identity was confirmed as Puccinia thaliae Dietel by nuclear ribosomal large subunit (28S) DNA sequencing with rust-specific primers (1). The sequence (deposited in GenBank as No. HQ434482), when blasted, was found to match sequence No. EU851154 of P. thaliae from C. indica with 98% identity (719 of 730 bp), the differences being attributed to a single insertion at bp 423 to 436 of sequence No. EU851154. The sequences of P. thaliae obtained from two different samples from Louisiana were identical and did not match any other sequence in GenBank. In North America P. thaliae is reported to cause rust on C. indica L. in Florida and C. × generalis in Texas, as well as on two members of the Marantaceae (Maranta arundinacea L. and Thalia geniculata L.) in Florida and M. arundinaceae in Mexico (2). To our knowledge, this is the first report of P. thaliae in Louisiana on Canna lily. Voucher materials (C. × generalis = LSU00123378 and C. indica = LSU00123384) have been deposited in the Bernard Lowy Mycological Herbarium (LSUM). References: (1) M. C. Aime. Mycoscience 47:112, 2006. (2) D. F. Farr and A.Y. Rossman. Fungal Databases. Systematic Mycology and Microbiology Laboratory, ARS, USDA. Retrieved 12 February from http://nt.ars-grin.gov/fungaldatabases/ , 2010.

A higher-rank classification for rust fungi, with notes on genera.

The rust fungi (Pucciniales) with 7000+ species comprise one of the largest orders of Fungi, and one for which taxonomy at all ranks remains problematic. Here we provide a taxonomic framework, based on 16 years of sampling that includes ca. 80 % of accepted genera including type species wherever possible, and three DNA loci used to resolve the deeper nodes of the rust fungus tree of life. Pucciniales are comprised of seven suborders - Araucariomycetineae subord. nov., Melampsorineae, Mikronegeriineae, Raveneliineae subord. nov., Rogerpetersoniineae subord. nov., Skierkineae subord. nov., and Uredinineae - and 18 families - Araucariomycetaceae fam. nov., Coleosporiaceae, Crossopsoraceae fam. nov., Gymnosporangiaceae, Melampsoraceae, Milesinaceae fam. nov., Ochropsoraceae fam. & stat. nov., Phakopsoraceae, Phragmidiaceae, Pileolariaceae, Pucciniaceae, Pucciniastraceae, Raveneliaceae, Rogerpetersoniaceae fam. nov., Skierkaceae fam. & stat. nov., Sphaerophragmiaceae, Tranzscheliaceae fam. & stat. nov., and Zaghouaniaceae. The new genera Araucariomyces (for Aecidium fragiforme and Ae. balansae), Neoolivea (for Olivea tectonae), Rogerpetersonia (for Caeoma torreyae), and Rossmanomyces (for Chrysomyxa monesis, Ch. pryrolae, and Ch. ramischiae) are proposed. Twenty-one new combinations and one new name are introduced for: Angiopsora apoda, Angiopsora chusqueae, Angiopsora paspalicola, Araucariomyces balansae, Araucariomyces fragiformis, Cephalotelium evansii, Cephalotelium neocaledoniense, Cephalotelium xanthophloeae, Ceropsora weirii, Gymnotelium speciosum, Lipocystis acaciae-pennatulae, Neoolivea tectonae, Neophysopella kraunhiae, Phakopsora pipturi, Rogerpetersonia torreyae, Rossmanomyces monesis, Rossmanomyces pryrolae, Rossmanomyces ramischiae, Thekopsora americana, Thekopsora potentillae, Thekopsora pseudoagrimoniae, and Zaghouania notelaeae. Higher ranks are newly defined with consideration of morphology, host range and life cycle. Finally, we discuss the evolutionary and diversification trends within Pucciniales. Citation: Aime MC, McTaggart AR (2020). A higher-rank classification for rust fungi, with notes on genera. Fungal Systematics and Evolution 7: 21-47. doi: 10.3114/fuse.2021.07.02.

First Report of Plumeria spp. Rust Caused by Coleosporium plumeriae in Louisiana and Malaysia and Catheranthus roseus, a New Host of this Rust.

Plumeria spp., native to tropical America, are popular small trees grown widely in tropical areas of the world and as potted plants elsewhere. P. rubra and P. obtusa cultivars and hybrids are most common. A rust disease of a Plumeria sp. (likely P. rubra based on pointed leaf tips, leaves more than 18 cm (7 inches) long, and high rust susceptibility) was observed in November 2008 and again in June 2009 on homeowner plants in Baton Rouge, LA. A survey of five Baton Rouge retail nurseries in September 2009 revealed that 87% (90 of 103) of the plumeria plants were heavily infected with rust. Early symptoms included numerous 1-mm chlorotic spots on adaxial leaf surfaces followed by leaf chlorosis, necrosis, and abscission. Uredinia were numerous, mostly hypophyllous and yellowish orange. Urediniospores were catenulate, orange en masse, verrucose, globose, ovoid, ellipsoidal or angular, and measured 21.8 to 41.9 × 16.4 to 32.8 µm (average 29.4 × 22.6 µm). The rust was identified as Coleosporium plumeriae Pat. (= C. plumierae) (3). Teliospores were not found during this study. Pathogenicity tests were performed by spraying urediniospores (20,000/ml of deionized water) on three healthy Thai hybrid plumeria plants. Five leaves of each plant were misted with water and covered with plastic bags and three to five leaves were inoculated. Plants were held at 27°C for 27 h in a dew chamber and then moved outdoors. Typical rust symptoms and uredinia with urediniospores developed in 10 days on all inoculated leaves while noninoculated leaves remained healthy. Characteristics and spore measurements matched those of the rust from original infected plants. Additional plumeria rust inoculations were made to other Apocynaceae family members that included Allamanda cathartica, Catheranthus roseus (Madagascar periwinkle), Mandevilla splendens, Nerium oleander, and Vinca major. Catheranthus roseus was very susceptible to C. plumeriae with chlorotic leaf spots developing on the six inoculated plants after 8 days and uredinia with urediniospores appearing after 11 days. None of the other plant genera were susceptible to the rust. Plumeria rust was also observed on plumeria trees in urban landscapes in peninsular (Penang) and Bornean (Kota Kinabalu, Sabah) Malaysia in December 2007. To confirm identity, ~1,000 bp of nuclear rDNA 28S subunit from each (Lousiana, Penang, and Kota Kinabalu) was sequenced with rust-specific primers (1) and shared 100% identity (GenBank No. GU145555-6). Plumeria rust was first found on the island of Guadeloupe (3) and then spread to Central and South America. It has been known from Florida since 1960 under the synonym C. domingense (2), but has not been reported elsewhere in the continental United States. In more recent years, plumeria rust has spread to Hawaii, many Pacific islands, India, China, Taiwan, Thailand, Australia, and Nigeria (4). To our knowledge, this is the first report of plumeria rust from Louisiana and Malaysia and of susceptibility of another member of the Apocynaceae, Madagascar periwinkle, to C. plumeriae. Voucher material from Louisiana and Malaysia has been deposited in the Mycology Herbarium of Louisiana State University (LSUM). References: (1) M. C. Aime. Mycoscience 47:112, 2006. (2) Anonymous. Index of Plant Diseases in the United States. U.S. Dept. Agric. Handb. No. 165. Washington, D.C., 1960. (3) N. Patouillard. Bull. Soc. Mycol. Fr. 18:171, 1902. (4) C. To-Anun et al. Nat. Hist. J. Chulalongkorn Univ. 4:41, 2004.

First Report of Rust Disease Caused by Puccinia sparganioides on Spartina alterniflora in Louisiana.

Spartina alterniflora Loisel. (smooth cordgrass) is the dominant plant species of intertidal salt marshes in the Atlantic and Gulf Coast regions of the United States. It is a perennial deciduous grass that can reduce and reverse coastal erosion by buffering wave energy and storm surges and by accumulating suspended solids from intertidal waters. Therefore, smooth cordgrass is utilized extensively in coastal restoration projects in Louisiana. In July 2009, smooth cordgrass leaf samples with signs and symptoms of a rust disease were collected from plant material grown at the Aquaculture Research Station near Baton Rouge, LA. Numerous hypophyllous, narrow, linear lesions were observed in which the uredinia were pale orange, erumpent, and arranged seriately. Urediniospores were yellowish to orange, obovoid to oblong, echinulate with a thickened apical wall and obscure germ pores, and measured 27.5 to 44.9 (-48.3) × 17.3 to 27.6 (-31.05) µm. Telia and teliospores were not observed. The pathogen was identified as Puccinia sparganioides Ellis & Tracy based on the DNA sequence of nuclear ribosomal large subunit (28S) and internal transcribed spacer region 2 (ITS-2) amplified with rust-specific primers (1). The sequence (deposited in GenBank as No. GU327649) was found to share 99.8% identity (1,077/1,079 bp) with sequence No. GU058027 of P. sparganioides from S. patens (Aiton) Muhl. and did not match any other species of Puccinia in GenBank. P. sparganioides has previously been reported on S. alterniflora in Connecticut, Delaware, Florida, Maine, Massachusetts, Mississippi, North Carolina, New Hampshire, Rhode Island, Vermont, and Virginia (2). To the best of our knowledge, this is the first report of P. sparganioides on S. alterniflora from Louisiana. Efforts to screen for rust-resistant lines for use in coastal restoration projects are underway to prevent land loss that could occur due to smooth cordgrass stress from infection. Voucher material (LSU00121657) has been deposited in the Bernard Lowy Mycological Herbarium (LSUM). References: (1) M. C. Aime. Mycoscience 47:112, 2006. (2) D. F. Farr and A. Y. Rossman. Fungal Databases. Systematic Mycology and Microbiology Laboratory, Online publication. ARS, USDA, October, 2009.

First Report of Rust Caused by Puccinia similis on Artemisia tridentata in Idaho and Oregon.

Artemisia tridentata Nutt. (Asteraceae), commonly called sagebrush or big sagebrush, is a coarse, hardy, silvery-gray bush growing in arid sections of the Great Basin Desert of intermountain plateau covering portions of California, Idaho, Nevada, Oregon, Utah, and Wyoming in the western United States. Sagebrush is a key component of these ecosystems, providing canopy cover, nesting habitat, and a food source for numerous species of small animals and birds (4). During a plant disease survey in the Treasure Valley Region of southwestern Idaho and eastern Oregon, symptoms and signs of rust were observed on leaves of sagebrush in July 2007. Ten of fifteen plants (~70%) observed at the site were infected. Leaf samples of sagebrush with rust were also collected from a hedge in a home garden in Canyon County, ID in May 2006 and September 2007. Symptoms on both samples included cinnamon-brown, raised uredinia, primarily on the adaxial leaf surfaces. Initially, sori were scattered, increasing in density and becoming confluent. Urediniospores were thick walled, subglobose to obovoid, golden brown, echinulate, with three +/- equatorial germ pores, and measured 28 to 32 × 23 to 27 µm. Telia appeared late in the season (July to August) and were mostly scattered, becoming confluent and forming raised, ovoid, brown-to-dark red streaks on leaves and stems. Teliospores were brown to dark red, two-celled, averaging 45 × 26 µm, thick walled (average 0.75 to 1.5 µm), thickening at the apex, ellipsoid to broadly ellipsoid, with thin-walled, hyaline pedicels, 26 to 31 µm broad at attachment, tapering below, equal to or up to twice as long as the spore. On the basis of morphology, this pathogen was identified as Puccinia similis Ellis & Everh. (2), an autoecious rust previously reported from Arizona and Wyoming on A. tridentata and A. nova A. Nels. (3). To confirm the identification of the specimens from Idaho, an ~1,000 bp of DNA from the ribosomal 28S large subunit was amplified and sequenced with rust-specific primers (1) (GenBank No. GU168942). Since there are no sequences of P. similis available in GenBank for comparison, a sequence of the same gene was also obtained from a specimen of P. similis that had been collected on A. cana Pursh in Utah in 1995 by C. T. Rogerson and deposited in the U.S. National Fungus Collections (BPI 863644; GenBank No. GU168943). The sequences shared 100% identity and did not match any other species of rust in GenBank. To our knowledge, this is the first report of P. similis in Idaho and Oregon on sagebrush, and the first report, based on herbarium data, of this rust on A. cana in Utah. Voucher specimens from Idaho have been deposited in BPI (878064) and the Bernard Lowy Mycological Herbarium (LSUM). References: (1) M. C. Aime. Mycoscience 47:112, 2006. (2) G. B. Cummins. Rust Fungi on Legumes and Composites in North America. University of Arizona Press, Tucson, 1978. (3) D. F. Farr et al. Fungal Databases. Systematic Botany and Mycology Laboratory, Online publication. USDA-ARS, 8 July 2009. (4) B. L. Welch and C. Criddle, USDA Forest Service Res. Pap. RMRS-RP-40. 2003.

First Report of Leaf Rust of Blueberry Caused by Thekopsora minima on Vaccinium corymbosum in the Western Cape, South Africa.

Southern highbush blueberry plants (Vaccinium corymbosum interspecific hybrids) showing rust-like symptoms were observed in July 2006 in Porterville in the Western Cape (WC), South Africa. Diseased plants were also found in Villiersdorp and George in the WC in 2007. In 2008, symptoms were observed in George, and in 2009, in all the previous reported areas. Cvs. Bluecrisp, Emerald, Jewel, Sharpblue, and Star were infected. Reddish-to-brown spots appeared on the adaxial surface of leaves and developed into yellow-to-orange erumpent uredinia with pulverulent urediniospores. Uredinia were hypophyllous, dome shaped, 113 to 750 µm wide, and occasionally coalescing. Urediniospores were broadly obovate, sometimes ellipsoidal or pyriform, with yellowish orange content, and measured 19 to 27 × 12 to 20 µm (average 24 × 15 µm, n = 30). Spore walls were echinulate, hyaline, 1 to 1.5 µm thick, and with obscure germ pores. No telia or teliospores were observed. Voucher specimens were lodged in the South African National Fungus Collection in Pretoria (PREM 60245). The isolate was initially identified as Thekopsora minima P. Syd. & Syd., based primarily on the absence of conspicuous ostiolar cells characteristic of Naohidemyces spp. (3). Genomic DNA was extracted from urediniospores. Approximately 1,400 bp were amplified spanning the 5.8S, ITS2, and 28S large subunit of the ribosomal DNA (1). The sequence (GU355675) shared 96% (907 of 942 bp; GenBank AF522180) and 94% (1,014 of 1,047 bp; GenBank DQ354563) similarities in the 28S portion, respectively, to those of Naohidemyces vaccinii (Wint.) Sato, Katsuya et Y. Hiratsuka and Pucciniastrum geoppertianum (Kuehn) Kleb, two of the three known rust species of blueberry (2). Although no sequences of T. minima were available for direct comparison, phylogenetic analyses of the 28S region strongly supported the South African blueberry rust as congeneric with T. guttata (J. Schröt.) P. Syd. & Syd. (GenBank AF426231) and T. symphyti (Bubák) Berndt (GenBank AF26230) (data not shown). Four 6-month-old cv. Sharpblue plants were inoculated with a suspension (approximate final concentration of 1 × 105 spores per ml) of fresh urediniospores in a water solution with 0.05% Tween 20. After incubation at 20°C for 48 h under continuous fluorescent lighting, the plants were grown in a glasshouse (18/25°C night/day temperatures). Identical uredinia and symptoms developed approximately 3 weeks after inoculation on the inoculated plants, but not on two control plants of cv. Sharpblue sprayed with distilled water and kept at the same conditions. The alternate host hemlock (Tsuga spp.) is not endemic to South Africa and not sold as an ornamental plant according to a large conifer nursery. Hosts of T. minima include Gaylussacia baccata, G. frondosa, Lyonia neziki, Menziesia pilosa, Rhododendron canadense, R. canescens, R. lutescens R. ponticum, R. prunifolium, R. viscosum, V. angustifolium var. laevifolium, V. corumbosum, and V. erythrocarpon (3). Visual inspection of possible hosts in the gardens in close proximity of Vaccinium production areas did not show any rust symptoms. To our knowledge, this is the first report of T. minima on blueberries outside of Asia and the United States (2). References: (1) M. C. Aime. Mycoscience 47:112, 2006. (2) D. F. Farr and A. Y. Rossman. Fungal Databases. Systematic Botany and Mycology Laboratory. Online publication. USDA-ARS, 2009. (3) S. Sato et al. Trans. Mycol. Soc. Jpn. 34:47, 1993.

Red yeasts from leaf surfaces and other habitats: three new species and a new combination of Symmetrospora (Pucciniomycotina, Cystobasidiomycetes).

Our understanding of the systematics of red yeasts has greatly improved with the availability of sequence data and it is now clear that the majority of these fungi belong to three different classes of Pucciniomycotina (Basidiomycota): Agaricostilbomycetes, Cystobasidiomycetes, and Microbotryomycetes. Despite improvements in phylogenetic placement, the taxonomy of these fungi has long been in need of revision and still has not been entirely resolved, partly due to missing taxa. In the present study, we present data of culture-based environmental yeast isolation, revealing several undescribed species of Symmetrospora, which was recently introduced to accommodate six species previously placed in the asexual genera Sporobolomyces and Rhodotorula in the gracilis/marina clade of Cystobasidiomycetes. Based on molecular phylogenetic analyses of three rDNA loci, morphology, and biochemical studies, we formally describe the following new species: Symmetrospora clarorosea sp. nov. from leaf surfaces in Portugal and the USA; S. pseudomarina sp. nov. from leaf surfaces in Brazil, and the USA and decaying wood in the USA; and S. suhii sp. nov. from a beetle gut in the USA, leaf surfaces in Brazil and marine water in the Taiwan and Thailand. Finally, we propose a new combination for Sporobolomyces oryzicola based on our molecular phylogenetic data, Symmetrospora oryzicola comb. nov.

New species of Entolomataceae from Cameroon.

Six species of Entoloma (Entolomataceae, Agaricales, Basidiomycota) are described from recent Cameroonian collections: E. bisterigmatum, E. brunneoloaurantiacum, E. djaense, E. intricatum, E. versiforme, and E. parvistellatum.These species occur in tropical rainforests dominated by ectomycorrhizal trees in the genera Gilbertiodendron and Uapaca. Data on macromorphology, micromorphology, DNA sequences, habitat and comparisons with similar taxa are provided for each. This is the first contemporary taxonomic work on the Entolomataceae from Cameroon.

First Report of Powdery Mildew Caused by Podosphaera xanthii on Sechium edule in the United States.

Sechium edule (Jacq.) Sw., also known as mirliton or chayote, is a perennial, monoecious, cucurbitaceous plant native to Mexico and Central America. It is cultivated worldwide for a variety of uses (4). Mirliton fruit is rich in carbohydrates, has 16 amino acids, and is a traditional staple in New Orleans, LA. During the spring of 2009, the LSU AgCenter's Plant Disease Diagnostic Clinic received diseased mirliton plants from a small commercial grower in New Orleans. Symptoms included yellow, irregular spots on both surfaces of the leaves. Microscopic examination revealed the presence of powdery mildew conidia and conidiophores. Initially, white, cottony mycelial colonies were present on the abaxial surface, but as the disease progressed, white, cottony colonies developed on the adaxial surface, the spots coalesced, and the entire leaf turned yellow and necrotic. Conidia were hyaline, ovoid, borne in long chains with crenate edges, and measured 25.6 to 36.6 µm long (mean = 31.2) × 14.6 to 18.3 µm wide (mean = 17.1). Conidia contained fibrosin bodies and produced a lateral germ tube with a simple appressorium. Conidiophores were erect, simple, unbranched, and measured 54.9 to 76.9 µm long (mean = 66.4) × 11.0 to 14.6 µm wide (mean = 12.9). The cylindrical foot cell had a simple base with basal septum adjacent to the mycelium. No teleomorph was observed. Morphologically, this powdery mildew fits either Podosphaera fusca or P. xanthii so DNA analysis was conducted. We designed Podosphaera-specific primers PFITS-F (5'-CCAACTCGTGCTGTGAGTGT-3') and PF5.8-R (5'-TGTTGGTTTCTTTTCCTCCG-3') to amplify and sequence the internal transcribed spacer region (ITS) of the nuclear rDNA. The 331-bp sequence (GenBank Accession No. GQ902939) was identical with haplotype 27 of P. fusca (GenBank Accession No. AB040324) (3), which is now called P. xanthii (1). Pathogenicity tests were conducted by pressing infected leaves against healthy leaves of two vines. A noninoculated vine served as a control. Plants were maintained in a greenhouse at 30°C. Five days after inoculation, yellow, irregular spots appeared on the inoculated vines and white, powdery mildew colonies appeared on the abaxial surface. Spots coalesced and the entire leaf turned yellow 8 days after inoculation and necrotic 12 days after inoculation. No symptoms developed on the controls. On the basis of DNA sequence data, this powdery mildew is identified as P. xanthii sensu (1). Erysiphe cichoracearum has been previously reported to cause powdery mildew on mirlitons in Florida and Hawaii (2). To our knowledge, this is the first report of powdery mildew caused by P. xanthii on mirliton in the United States. A voucher specimen has been deposited in the Bernard Lowy Mycological Herbarium (LSUM 185359). References: (1) U. Braun and S. Takamatsu. Schlechtendalia 4:31, 2000. (2) D. F. Farr and A. Y. Rossman. Fungal Databases. Systematic Mycology and Microbiology Laboratory, SMML, Online publication. USDA-ARS, 2009. (3) T. Hirata et al. Can. J. Bot. 78:1521, 2000. (4) M. Janssens et al. Tropical Crops. ARTS; Field and Vegetable Crops, PTS 130. Bonn, Germany, 2002/03.

First Report of Bamboo Rust Caused by Kweilingia divina on Bambusa domestica in Los Angeles County, California.

Elongate, interveinal, hypophyllous lesions were observed on bamboo plants (Bambusa domestica) during an inspection of a plant shipment in November of 2006 in Los Angeles County, CA. Disease incidence was 100%. Minute uredinia were spaced at regular intervals within each lesion. Urediniospores were pale tan, echinulate, and 18 to 29 × 16 to 23 µm with 1- to 1.5-µm walls. The urediniospores were surrounded and partially covered by incurved pale-to-brownish yellow paraphyses 34 to 45 × 12 µm with walls that were primarily thickened apically and dorsally to 5 µm. Several telia were observed forming inside old uredinia. Telia were brownish black, forming a flabellar head of teliospores fused laterally and in chains of three to six cells. Teliospores were chestnut brown, cuboidal to oblong, and measured 10 to 12.5 × 12.5 to 25 µm. DNA sequence of the 28S large subunit nuclear ribosomal DNA was obtained using previously published methods (1). The sequence deposited in GenBank as Accession No. EF192212 matched sequence No. DQ354554 (1), Kweilingia divina from Costa Rica (1), with 100% identity. On the basis of morphological characteristics (2) and sequence information, the rust was identified as K. divina (Syd.) Buriticá (= Dasturella divina (Syd.) Mundk. & Khesw.), causal agent of bamboo rust. Bamboo rust is widespread in parts of Asia but has also been found in Africa, Colombia, Brazil, Central America (3), and Australia (4). The shipment was traced to a foliage plant producer in Hawaii where the disease was subsequently found in the environment on the four major Hawaiian Islands of Oahu, Hawaii, Kauai, and Maui. All 10 bamboo plants received by the nursery were located and destroyed. To the best of our knowledge, this is the first report of bamboo rust occurring in California. References: (1) M. C. Aime. Mycoscience 47:112, 2006. (2) G. B. Cummins. Page 43 in: The Rust Fungi of Cereals, Grasses and Bamboos. Springer-Verlag, New York, 1971. (3) D. F. Farr et al. Fungal Databases, Systematic Mycology and Microbiology Laboratory. Online publication. ARS, USDA, year. (4) G. I. Johnson. Australas. Plant Pathol. 14:54, 1985.