Telia Research Articles

Rust fungi (Pucciniales) on Cyperaceae in Japan, with 2 new names, 5 new combinations and typifications

Rust fungi (Pucciniales) producing uredinial and/or telial stages on species of Cyperaceae in Japan are listed based on literature records. Host plants and distribution of 92 species (86 species of Puccinia, 5 species of Uromyces and 1 species of Uredo) are described. Among them two new names and five new combination names are proposed in accordance with the Shenzhen Code, ICNafp. Type specimens (neotypes, lectotypes, epitypes, paratypes) for 29 species are selected and designated. One hundred species of Cyperaceae (22.9% of species reported in Japan) including ten genera are recorded as their host plants of uredinial and/or telial stages. Spermogonial and aecial stages of 36 species are confirmed and 59 species of plants including 14 families 29 genera are also described as their hosts.

First Report of the Rust Fungus Melampsora ferrinii on Salix babylonica in China and a New Spermogonial and Aecial Host, Corydalis bungeana.

The occurrence of rust fungi on Corydalis bungeana Turcz. and Salix babylonica L. were found in same area of Hebei Province, China from 2022 to 2023. The life cycle connection of these rust fungi was suspected because Peng et al. (2022) reported the life cycle of Melampsora ferrinii Toome & Aime by inoculations, producing spermogonia and aecia on Corydalis species, and uredinia on S. babylonica. The morphology of the uredinial and telial stages on S. babylonica collected in the field was identical with the description of M. ferrinii by Toome and Aime (2015), and its identity was confirmed by phylogenetic analyses using the method of Ji et al. (2020) (LSU-PP087777, ITS-PP091274; Similarity with M. ferrinii: LSU-100%, ITS-99.85%). To confirm the life cycle of this rust fungus, inoculations were conducted on C. bungeana with basidiospores obtained from the teliospores on fallen leaves of Salix babylonica. The fallen leaves producing basidiospores were cut into small pieces (ca. 5 mm2) and placed on healthy leaves of C. bungeana. The inoculated plants were kept in a moist plastic box in darkness at 15-20℃ for 2 days and then transferred to the floor near windows at about 15-20℃ for observations. Ten days after inoculations small yellow spots of spermogonia appeared on the upper surface of the leaves of C. bungeana. About 7 days later, pale yellow aecia with aeciospores were produced mainly on the under surface of the leaves and petioles. The morphology of rust fungus on C. bungeana collected from the fields and obtained by inoculations was identical with the description by Peng et al. (2022). Phylogenetic analyses also showed that a specimen on C. bungeana collected from the field (LSU-OR607838, ITS-OR612063) were included into the same clade of M. ferrinii (Similarity: LSU-100 %, ITS-99.85). Based on morphology, inoculations and DNA sequence analyses, the rust fungi on C. bungeana and S. babylonica are identified as different stages of life cycle of M. ferrinii. This rust fungus has been reported to produce spermogonia and aecia on C. acuminata Franch., C. edulis Maxim. and C. racemosa (Thunb.) Pers. in China (Peng et al. 2022), and uredinia and telia on S. babylonica in USA, Argentina and Iran (Toome and Aime 2015, Abbasi et al. 2024), and on Salix sp. in Chile (Zapata 2016). Therefore, C. bungeana is a new host for M. ferrinii, and its field occurrence on S. babylonica is reported for the first time in China although Peng et al. (2022) reported successful results in its inoculations to S. babylonica in China. This report contributes to the control of rust diseases caused by this species. Specimens used in this experiment were deposited in the Fungal Herbarium of the Jilin Agricultural University, Changchun, China (HMJAU) and sequences newly analyzed were deposited in GenBank.

The exotic rust fungus Puccinia abrupta var. partheniicola on the invasive alien weed Parthenium hysterophorus in India: rediscovery and first report of an epiphytotic

Puccinia abrupta var. partheniicola, the so-called winter rust of parthenium weed (Parthenium hysterophorus), an invasive alien weed in India, was rediscovered at an epiphytotic scale in February 2023 following a prolonged period of presumed absence in the field. Disease incidence was 80–90% in large tracts of P. hysterophorus stands along the roadsides in an area of 5 km2 near Attibele–Sarjapura road (948A) in Anekal taluk of Bengaluru Urban district in Karnataka. Pycnial, aecial or telial stages of the rust were not found. The morphological parameters of uredinia and urediniospores completely matched those originally described, thus confirming the fungal identity. The significance of this rust epiphytotic to P. hysterophorus biocontrol in India is discussed together with the planned follow-up activities.

<i>Puccinia scirpi</i> – first finding of the fungus in the uredinial stage and new notes of the aecial and telial stages in Poland

<i>Puccinia scirpi</i> – first finding of the fungus in the uredinial stage and new notes of the aecial and telial stages in Poland

Occurrence of rust disease Caused by Gymnosporangium pleoporum on Cotoneaster acutifolius in China.

Species of Gymnosporangium are major pathogenic rust fungi causing diseases and significant economic losses of plants in the Cupressaceae and Rosaceae family (Kern 1973). During our investigation of rust fungi in Qinghai Province, northwestern China, we found the spermogonial and aecial stages of Gymnosporangium species on Cotoneaster acutifolius. C. acutifolius is the woody plant that range in habit from ground-covers to airy shrubs and medium-sized trees(Rothleutner et al. 2016). Upon investigation in the field, the incidence of rust on C. acutifolius was 80% and 60% (n = 100) for 2020 and 2022, respectively. C. acutifolius leaves showing abundant aecia were collected from Batang forest area of Yushu (32.45°N, 97.19°E, alt. 3835 m), Qinghai, China, from August to October of both years. The rust makes its symptom first on the upper surface appearing yellow then dark brow, aggregated spermogonia in yellow-orange leaf spots. These spots enlarge gradually and displaying an orange-yellow and are often bordered by red concentric rings. In the later stage, many pale yellow, roestelioid aecia developed on the abaxial surfaces of the leaves or fruits. The morphology of this fungus was studied using light microscopy and scanning electron microscopy (JEOL, JSM-6360LV). Microscopic examination show that aecia are foliicolous, hypophyllous, roestelioid, and producing cylindrical peridia that are acuminate, splitting above and becoming some-what lacerate nearly to base, somewhat erect after dehiscence. Peridial cells are rhomboid, and 42 to 118 × 11-27μm(n=30). They have smooth outer walls and rugose inner and side walls with long obliquely arranged ridges. Aeciospores are ellipsoid, chestnut brown, 20 to 38 × 15 to 35 μm(n=30), wall densely and minutely verrucose, 1 to 3 μm thick, with 4 to 10 pores. Whole genomic DNA was extracted (Tian et al. 2004), and the internal transcribed spacer 2 (ITS2) region was amplified with the primer pair ITS3 (Gardes and Bruns 1993) and ITS4 (Vogler and Bruns 1998). The sequence of the amplified fragment was deposited in the GenBank database (GenBank Accession No. MW714871). A BLAST search of GenBank showed a high identity (> 99%) with the reference sequences of Gymnosporangium pleoporumGenBank Accession No. MH178659 and MH178658). G. pleoporum was first described from specimens in the telial stage found on Juniperus przewalskii, from Menyuan of Qinghai in China (Tao et al. 2020). In this study, the fungus G.pleoporum of spermogonial and aecial stages were collected from the C. acutifolius, we confirmed the alternate host of G. pleoporum based on DNA extraction results. To our knowledge, this is the first record of G. pleoporum causing rust disease on C. acutifolius. Because the alternate host can be infected by several different species of Gymnosporangium (Tao et al. 2020), further investigations are needed to verify heteroecious of the rust fungus.

Ultrastructural studies of the host (Senecio aegyptius L.) responses after the infection by the pathogenic rust fungus, Puccinia lagenophorae Cooke

This study investigated the impact of the rust fungus, Puccinia lagenophorae on its host, Senecio aegyptius using both light (LM) and transmission (TEM) electron microscopy. The chloroplast numbers decreased during the aecial and telial stages of the pathogen (53.7 and 56.6%, respectively). The nucleus volumes were increased during both stages (10.9 and 14.1%, respectively). Infected chloroplasts and nuclei showed changes in their shape and ultrastructure. Instead of the M-haustorium, a collar was created around the D-haustorium. A neck encasing developed in both types of necrotic haustoria. This encasement may serve as the host cell’s protection against toxins created after the death of haustoria. The severe changes in the chloroplasts and nuclei of this host plant after infection by this pathogen may give this pathogen the possibility of controlling this serious weed. Future research in the molecular mechanism may explore the biological control of weeds for local farm agroecology.

Electron microscopy of the uredinial and telial stages of the rust fungus, Puccinia imperatae

The purpose of this work was to assess the morphology and ontogeny of Puccinia imperatae urediniospores and teliospores growing on its host, Imperata cylindrica, for the first time using scanning (SEM) and transmission (TEM) electron microscopy. The first evidence of uredinial development is the aggregation of hyphae in host intercellular spaces under the epidermis to form an uredinial initial. Uredinial primordia become evident as compact masses of fungal hyphae. The mycelia are dikaryotic and originated from dikaryotic urediniospores, which infect a new host. Dikaryotic sporogenous cells begin to form from dikaryotic mycelium as the uredinium develops further. The fundamental cell in the urediniospore and teliospore formation is the sporogenous cell. The teliospores with their persistent pedicels arise from dense dikaryotic sporogenous tissue, which later becomes highly vacuolated. The sporogenous cell forms a spore bud, which later divides into a pedicel and teliospore mother cell with two nuclei that produce the mature teliospore. SEM examination revealed that the urediniospores are echinulate bearing conical spines on their surfaces, sometimes curving near their tips, and the echinulate ornaments are distributed over the entire urediniospore surface. SEM examination also indicated that the teliospore surface shows rugose ornamentations. This investigation proved that the morphology of the uredinia of different Puccinia species is not related to the host species, but to the rust species. The possibility of using this fungus as a biological control agent for the noxious weed, Imperata cylindrica, was also discussed.

Rust on Hosta longipes caused by Puccinia oncospora in Korea

Hosta longipes (Liliaceae), widely distributed throughout Korea, China, Japan, and eastern Russia, is one of the most popular ornamental perennials in public and private gardens. In Korea, this species has long been used as a traditional medicine for the treatment of coughs, phlegm, burns, swelling and asthma (Kim et al., 2014), and its young leaves are also consumed as a salad vegetable. In June 2016, rust disease was observed on H. longipes plants growing naturally around a stream at Mount Gongjaksan in Hongcheon-gun, Korea (Fig. 1). The disease incidence rate was c. 10%. Symptoms appeared as yellowish, round, chlorotic spots on the upper surface of the infected leaves (Fig. 2) and yellow to orange-coloured aecia on the corresponding lower surface and petiole (Fig. 3). After the first findings, the same disease was observed in 2017, 2019 and 2020. Herbarium specimens of infected material were deposited in the Korea University Herbarium (Accession Nos. KUS-F29182, F29810, F30967, and F31685). Leaves affected by the rust infection were examined under a dissecting microscope (M205C; Leica, Germany), a DIC microscope (Axio Imager 2; Carl Zeiss, Germany), and a scanning electron microscope (S-4800+EDS; Hitachi, Japan). Spermogonia were mostly epiphyllous but rarely hypophyllous, densely grouped, pale brown, and subepidermal. Aecia were hypophyllous, often densely grouped, yellow, cupulate with peridia, and 196–300 μm in diameter (Fig. 4). Aeciospores were hyaline, globose to subglobose, angular, and (20.2-)22.0-24.9(-27.4) × (17.0-)19.6-22.5(-24.2) μm (mean 23.4 × 21.0 μm) (Fig. 5). Aeciospore wall was densely verrucose and 0.6-1.6 μm (mean 1.0 μm) in thickness (Fig. 6). Uredinial and telial stages were not observed. These morphological characteristics were consistent with those of Puccinia oncospora (Ji et al., 2022). To confirm the morphology-based identification, genomic DNA was extracted from four specimens using a MagListo 5M plant Genomic DNA Extraction Kit (Bioneer, Korea). Two ribosomal DNA regions were amplified: the internal transcribed spacer (ITS) with primers ITS5u and ITS4rust (Pfunder et al., 2001) and the large subunit (LSU) rDNA with primers LRust1R and LRust3 (Beenken et al., 2012). The resulting sequences were deposited in GenBank (Accession Nos. OQ061206-9 for ITS and OQ073721-4 for LSU) and compared to other reference sequences using BLASTn. The ITS sequences of Korean specimens were identical to those of P. oncospora ex Trillium kamtschaticum and Phalaris arundinacea for ITS (MW404821-5) and LSU sequences (MW404981-5). In maximum-likelihood phylogenetic trees for ITS (Fig. 7A) and LSU (Fig. 7B) sequences, the Korean samples were grouped with the reference sequences of P. oncospora with high bootstrap supporting values of 93% in ITS and 96% in LSU. Puccinia oncospora is a recently described rust species that is so far only known from China, where it completes its life cycle by forming an aecial stage on Trillium kamtschaticum (Melanthiaceae, previously Liliaceae) and a telial stage on Phalaris arundinacea (Poaceae; Ji et al., 2022). So far, three species of Puccinia have been recorded on Hosta longipes, namely, P. funkiae, P. hemerocallidis, and P. majanthemi (Hiratsuka & Sato, 1951; Farr & Rossman, 2022). Also, a species complex P. sessilis was considered parasitic on H. longipes (Hiratsuka & Sato, 1951), but it is phylogenetically and morphologically distinguishable from P. oncospora. To our knowledge, this is the first record of rust disease on Hosta longipes and this rust pathogen in Korea. As there have been no records of rust on P. arundinacea, a telial host plant of P. oncospora, in Korea, finding an alternative host for that rust is necessary to develop effective control measures. This work was supported by the National Academy of Agricultural Science grant (PJ0149560112020) from the Rural Development Administration, Korea.

Puccinia caricis-smilacis, a new caricicolous rust fungus producing spermogonial and aecial stages on Smilax china in Japan.

Puccinia caricis-smilacis, a new species of caricicolous rust fungus was described based on morphological characteristics and nuclear rDNA sequences from Japan. The heteroecious life cycle of P. caricis-smilacis was elucidated via field observations, inoculation experiments and molecular analyses. This rust fungus produces uredinial and telial stages on Carex fibrillosa, and spermogonial and aecial stages on Smilax china.

First report of Phragmidium rubi‐oldhami causing rust disease on Rubus pungens in Korea

Rubus pungens (‘Korean creeping raspberry’; Rosaceae) is a deciduous, broad-leaved tree native to East Asia. Its edible fruit is consumed fresh or used as a medicinal ingredient for diabetes and asthma (Moon, 1991). In May 2021, symptoms of a rust disease were observed on Rubus pungens in the Korea National Arboretum, Pocheon, Korea, with a disease incidence of 50% amongst the 30 plants surveyed. Bright yellow-orange rust pustules of the uredinial stages were found on both sides of the infected leaves. The pustules were often erumpent and 1 to 3 mm in diameter (Figure 1). The infected leaves were examined under a light microscope. Uredinia (Figure 2; n = 20) were erumpent, round, yellow to pale yellow, mostly scattered, rarely grouped and 200–536 µm in diameter (Figure 2). Urediniospores (= 50) were hyaline, globose to sub-globose and (16.0–)18.4–21.2(–23.6) × (12.6–)15.3–18.5(–19.7) µm (mean 19.8 × 16.9 µm), with an echinulate wall of 1.0 µm thick (Figures 3, 4). Paraphyses (n = 30) were hyaline, oblong or curved, and 56.2–11.1 µm, with a thin wall of 0.5–1.0 µm, occasionally slightly thickened at apex, 1.2–2.5 µm (Figure 5). The telial stage was not found. Based on morphological characteristics, the rust fungus was identified as Phragmidium rubi-oldhami Togashi & Y. Maki (Hiratsuka, 1934). To confirm the identification of the rust, genomic DNA was extracted from a representative specimen (KSNUH1322). Two ribosomal DNA regions were amplified, the internal transcribed spacer (ITS) with primers ITS5u and ITS4rust (Pfunder & Schürch, 2001) and the large subunit (LSU) with primers LRust1R and LRust3 (Beenken et al., 2012). The resulting sequences were deposited in GenBank (Accession Nos. ON180674 for ITS and ON170371 for LSU). A BLASTn search revealed that the Korean isolate had 99.43% identity in the LSU region to the only P. rubi-oldhami sequence in Genbank, which was obtained from Rubus pungens in China (MG669116). Close identities were found with other Phragmidium species when analysing the ITS sequences, however, there is no ITS reference sequence in GenBank for P. rubi-oldhami. In a maximum likelihood phylogenetic analysis using ITS (Figure 6) and LSU (Figure 7) sequences, the Korean isolate grouped with the reference sequence of P. rubi-oldhami in the LSU tree and formed a distinct branch among other Phragmidium species in the ITS tree. Phragmidium rubi-oldhami was originally described as a rust on Rubus oldhami in Japan (Togashi & Maki, 1934) and has since been recorded on R. amabilis, R. pungens and R, thibetanus in China and Japan (Farr & Rossman, 2022; Liu et al., 2018; Zhuang & Wei, 2009). To our knowledge, this is the first report of P. rubi-oldhami and of the rust disease on R. pungens in Korea. Given that urediniospores can easily disperse long distances by wind, this can pose a potential risk of rust disease on other Rubus species in Korea. This work was supported by the Korea National Arboretum grant (KNA3-1-10, 21–4) from the Korea Forest Service, Korea.

First report of peanut rust caused by Puccinia arachidis on Arachis hypogaea in New Caledonia

In July 2021, Arachis hypogaea (peanut) plants exhibiting typical brown rust pustules were observed in a small organic farming plot in the municipality of Païta (La Tamoa) in the Southern Province on the west coast of Grande Terre, New Caledonia (Figures 1-3). The disease affected all of the foliage, accelerating the senescence of the plants and shortening the cultivation cycle by three to four weeks. This reduced the size of the harvested peanuts by about 20–30%. Symptomatic leaves with numerous rust sori on the underside were collected and examined. The urediniospores were mostly brown, ellipsoidal, finely echinulate, variable in size (20.6–26.2 × 19.3–21.8 μm), with brown walls (1.2–1.9 μm thick) and often with two equatorial germ pores (Figure 4). No teliospores were found. Based on urediniospore morphology, the pathogen was identified tentatively as Puccinia arachidis (Mondal & Badigannavar, 2015). Puccinia arachidis is known almost exclusively by its uredinial stage. The telial stage has only been reported from Central America, Florida, and Brazil on leaves of wild peanut (Hennen et al., 1976) and more recently from cultivated peanut in India (Tashildar et al., 2012). For molecular identification, urediniospores were carefully scraped and transferred into 2 ml microtubes containing 1 mm silica beads. DNA was extracted using a commercial plant DNA extraction kit (DNeasy Plant Mini Kit, Qiagen, USA). Total DNA was diluted 10-fold and the ITS2-LSU region of the rDNA was amplified by PCR using the Rust2inv (Aime, 2006) and LR6 (Vilgalys & Hester, 1990) primers. The PCR product was sequenced and deposited in GenBank (Accession No. OM516766). BLAST analysis of the 1319 bp sequence against the whole genome sequence of P. arachidis (LBLN01000600.1) showed 100% identity, confirming the morphological identification. To our knowledge, this is the first report of Puccinia arachidis in New Caledonia. On this island, groundnuts are rarely cultivated and not extensively monitored. Nevertheless, the presence of Puccinia arachidis could have an economic impact regarding the potential development of this crop in New Caledonia since it can lead to major yield losses and may significantly reduce the pod and oil quality (Mondal & Badigannavar, 2015). Puccinia arachidis remains a quarantine pathogen in New Caledonia.

Phylogenetic approach for identification and life cycles of Puccinia (Pucciniaceae) species on Carex (Cyperaceae) from northeastern China

About 150 species of Puccinia on Carex (Cyperaceae) have been reported globally. However, these species can be difficult to identify due to similarities in morphology and difficulties in identifying the host plants. The presence of many cryptic species is also suspected. Based on about 130 specimens on Carex and about 40 related specimens of spermogonial and aecial stages, all collected in northeastern China, a phylogenetic approach was conducted to clarify their identification and life cycles. In the phylogenetic analyses, 17 clades among specimens on Carex were detected. Each clade was interpreted as an independent species, although many clades were morphologically similar to each other. After comparative morphology with species previously reported, seven species including three first records in China (P. circaeae-caricis, P. urticae-inflatae and P. vaginatae) were identified, while ten species (P. caricis-artemisiae, P. caricis-atractylodes, P. caricis-hebeiensis, P. caricis-jilinensis, P. caricis-lactucae, P. caricis-pediformis, P. caricis-rafaensis, P. caricis-ribicola, P. caricis-tenuiformis and P. caricis-violae) are described as new. In uredinial and telial stages, many host plant species could not be identified as they lacked an inflorescence. Thus, a phylogenetic approach is more suitable for species identifications of Puccinia on Carex rather than relying on rust morphology and host plant identification. Life cycle relations for 12 spermogonial and aecial species were also clarified using phylogenetic analyses. Furthermore, it is suspected that Puccinia species on Carex can be differentiated into species based on their spermogonial and aecial stages on the same or related host plants. Additionally, one new replacement name (P. caricis-aphanolepidis) for P. pulchella is proposed.

Phylogenetic approach for identification and life cycles of Puccinia (Pucciniaceae) species on Poaceae from northeastern China

About 300 species of Puccinia on Poaceae have been reported globally. However, these species can be difficult to identify because of morphological similarities and difficulties of host plant identifications. The presence of many cryptic species is also suspected. Based on about 150 specimens on Poaceae and about 50 related specimens of spermogonial and aecial stages, all collected in northeastern China, a phylogenetic approach was conducted to clarify their identification and life cycles. In phylogenetic analyses 25 clades among specimens on Poaceae were detected. Each clade detected in phylogeny was interpreted as an independent species, although many clades were morphologically similar to each other. After comparative morphology with species previously reported, 17 species including three first records in China (P. cerienthes-agropyrina, P. coronati-agrostidis, P. coronati-hordei) were identified, and eight species (P. ampliaticoronata, P. digitaticoronata, P. eleganticoronata, P. elymi-albispora, P. oncospora, P. pileiformis, P. protuberanticoronata, P. ramificatacoronata) are described as new. In uredinial and telial stages, the host range of above 25 species was variable ranging from one host plant species to several host species, sometimes involving different grass genera. Thus, a phylogenetic approach is more suitable for species identifications of Puccinia on Poaceae rather than relying on rust morphology and host plant identification. Life cycle relations for 15 spermogonial and aecial species were also clarified by phylogenetic analyses. It is also suspected that grass rusts can be differentiated to species based on spermogonial and aecial stages on same or related host plants.

Study of Some Species of the Genus Gymnosporangium and its Host Plant Families in Al-Kadmous Region, Syria

Ghazal, I. and A. Shaheen. 2022. Study of Some Species of the Genus Gymnosporangium and its Host Plant Families in Al-Kadmous Region, Syria. Arab Journal of Plant Protection, 40(4): 286-292. https://doi.org/10.22268/AJPP-40.4.286292 This study was carried out to identify some rust fungi species of the genus Gymnosporangium and to determine their hosts in the Mediterranean mountain region of Al-Kadmous, Tartous Governorate, Syria, during the period 2017-2020. The identified species were described morphologically, and stages of their lifecycle was detected on each host plant and their occurrence (%) on mutual hosts was assessed. The monitoring of various tree species, which belong to the family Rosaceae (subfamily: Pomoideae) in addition to all species of cypress (Cupressaceae), has shown mainly the existence of four species belonging to Gymnosporangium: G. sabinae (Dicks.) Winter, G. gracile Pat., G. confusum Plowr. and G. clavariiforme (Wulfen) DC. The pycnia and the aecia stages were recorded on all cultivated pear trees (Pyrus sp.), and the wild pear or Syrian pear (Pyrus syriaca). The second species was found on the wild hawthorn (Crataegus azarolus and Crataegus monogyna) and quince (Cydonia sp.). As for the rest of the species, they were found only on wild hawthorn. In addition, the telial stage (Telia) of the four species was found on the primary or winter host juniper (Juniperus oxycedrus). Finally, it was noticed that the distribution of this genus depended entirely on the existence of the Juniper shrubs nearby the Pomoideae species. Keywords: Rust fungi, Gymnosporangium, Host Plant, Pomoideae, Juniper, Al- Kadmous Region, Syria.

First Report of Aloe vera Rust Caused by Uromyces aloes in an Ornamental Nursery in the United States.

Aloe vera (L.) Burm. f. is a tropical evergreen perennial in the family Liliaceae. Native to the Arabian Peninsula, it is sold in Pennsylvania as an ornamental and for its medical and topical purposes due to its high levels of amino acids, anthraquinones, saponins, and vitamins A, B, C, E (Sahu et al. 2013). In February 2020, at an ornamental plant nursery in Lancaster County, Pennsylvania, 5 out of 15 mature A. vera plants in 15 cm pots showed symptoms and signs of rust on the leaves, exhibiting dark-brown erumpent pycnial spots with a chlorotic band surrounding the infected tissue that turned necrotic after three days of incubation at 20°C. Only the telial stage was present. Sori (n=25) were rounded, concentrically arranged, 0.2-3.7 mm, and covered by a brown epidermis. Teliospores (n=40) were amphigenous, orange-brown, globose to ellipsoidal, measuring (29.2) 30.4-36.1 (39.5) × (27.4) 27.6-30.1 (30.5) µm, with a wall thickness of 4-5 µm, and a persistent hyaline pedicel ranging from 5 to 57.1 µm in length and 5.2 to 9.3 µm in width. These measurements were comparable to the descriptions of Uromyces aloes previously reported from India (teliospore size 25-42.5 x 20-30 µm, wall thickness 3-5 µm, and pedicel size 25-95 x 5-6.25 µm), and South Africa (teliospore size 30-44 x 24-32 µm, wall thickness 4-6 µm, and pedicel size 6-20 µm) (Maier et al. 2007; Soni et al. 2011). Based on these morphological traits and the plant host, the causal agent was identified as Uromyces aloes (Cooke) Magnus (Pucciniaceae, Uredinales). The sample was also independently identified as U. aloes by the USDA APHIS PPQ Beltsville lab (Interception # APEMD200552555001) based on morphological characteristics. Teliospores were harvested with a sterile pin, transferred to a 1.5 ml tube with DNA extraction buffer (100 mM Tris-HCL, 10 mM EDTA, 1 M KCl, pH 8) and macerated using a plastic mini-pestle. The DNA was precipitated using isopropanol, washed with 70% ethanol, and reconstituted in 50 µl of PCR-grade water. The segment of the internal transcribed spacer region (ITS) was amplified using ITS4/ITS5 primers (White et al. 1990). The nuclear ribosomal small subunit (18S) was amplified with rust specific primers Rust18S-R (Aime 2006) and NS1 (White et al. 1990). The nuclear ribosomal large subunit (28S) was amplified with primers LR0R and LR7 (Vilgalys et al. 1990). Amplified PCR products were cleaned using ExoSap (Affymetrix, Santa Clara, CA) or QIAquick PCR Purification Kit (Qiagen, Valencia, CA) and sequenced at Penn State Genomics Core Facility. The nucleotide sequences were trimmed, analyzed, and aligned using Geneious 11.1.5 software (Biomatters, Auckland, NZ). The resulting 692-bp segment of the ITS, 1,633-bp segment of the 18S, and the 1,324-bp segment of the 28S regions were deposited in the GenBank database under accession numbers MT136509, MZ146345, and MZ146342, respectively. Based on GenBank BLAST analysis, a 529-bp fragment of our 28S product was found to share 98.87% (523/529) identity with U. aloes isolate WM3290 (DQ917740) from South Africa, with three nucleotide differences and three gaps between the two strains. Comparisons among ITS and 18S sequences could not be made because no ITS or 18S sequence data from U. aloes has previously been deposited in GenBank. To our knowledge, this is the first report of U. aloes from A. vera in the United States. Infected plants were confined inside a greenhouse and have been destroyed. Since the plants were purchased from either Ontario, Canada or Florida, the extent of infection in the United States is unknown.

First Report of Gymnosporangium yamadae Causing Japanese Apple Rust on Crabapple (Malus spp.) in Ohio.

Japanese apple rust, caused by the heteroecious and demicyclic rust fungus Gymnosporangium yamadae Miyabe ex G. Yamada, can affect juniper (Juniperus spp.), where the telial stage of this disease occurs, and apple or crabapple (Malus spp.), where the aecial stage occurs (Yun, 2010). Leaf samples displaying symptoms and signs of rust disease were collected in August 2020 from 14 different crabapple cultivars ('Amerspirzam' [American Spirit®], 'Amsalzam' [American Salute™], 'Excazam' [Excalibur™], 'Guinzam' [Guinevere®], 'Hargozam' [Harvest Gold®], 'Mary Potter', 'Orange Crush', 'Prairie Maid', 'Professor Sprenger', 'Pumpkin Pie', 'Rawhide', 'Select A' [Firebird®], 'Shotizam' [Show Time™], 'Sinai Fire') in the crabapple research plot of Secrest Arboretum (Crablandia) in Wooster, OH. Samples displayed adaxial leaf lesions with brown necrotic centers surrounded by a red-yellow coloration, corresponding on the abaxial side to lesions containing brown-orange aecia, producing aeciospores, surrounded by a dark red-orange coloration (Supplemental Figure 1). One to multiple lesions were present per symptomatic leaf. DNA was extracted from symptomatic leaf tissue containing fungal material on all 14 cultivars using the DNeasy Plant Mini Kit (QIagen) and the D1/D2 region of the 28S rDNA was amplified using primers NL1 and NL4 (O'Donnell 1993) according to Dagar et al. (2011). GenBank BLAST sequence analysis of all 14 sequences resulted in 99.83-100% sequence identity to G. yamadae with with 99% query coverage (MN605735). Sequences from all samples were deposited in GenBank under Accession Nos. MW131119.2-131125.2 and MW131127.2-131132.2. Morphological features were characterized for the three representative cultivars 'Amerspirzam' (American Spirit®), 'Orange Crush' and 'Pumpkin Pie' (Supplemental Figure 2). Aecia were hypophyllous, roestelioid, with cornute, yellow-brown, peridia with lacerate sides. Peridial cells appeared yellow and were long-linear rhomboid, verrucose with long papillae, smooth outer walls and echinulate inner walls, measuring 45 - 78 × 16 - 27 µm (average 65 × 21 µm), 51 - 82 × 16 - 30 µm (average 66 × 23 µm), and 47 - 93 × 14 - 31 µm (average 64 × 24 µm), respectively (n=50 per cultivar). Aeciospores were globose, 20 - 26 × 18 - 24 µm (average 23 µm × 20 µm), 21 - 28 µm × 19 - 24 µm (average 24 µm × 21 µm), and 21 - 27 µm × 18 - 23 µm (average 23 µm × 21 µm), respectively, with a slightly coronate surface and dark yellow walls 1.6 - 2.7 µm (average 2 µm), 1.4 - 2.4 µm (average 2 µm), and 1.3 - 2.5 µm (average 1.8 µm) thick, respectively (n=50 per cultivar). The telia, known to occur on Juniperus spp., were not observed. Specimens from these three cultivars were deposited into the U.S. National Fungus Collections (BPI 923889, 923888, 923887). Japanese apple rust has been officially reported in parts of Eastern Asia and the Eastern United States and is also known to be present in parts of Far East Russia and Ontario, Canada (Yun et al., 2009; CAB International, 2008). This report constitutes the first confirmed instance of G. yamadae causing Japanese apple rust in Ohio. Because infected trees tend to be highly symptomatic, this disease poses a significant threat to the nursery and landscape industries as it can decrease the market value of ornamental varieties and affect yield and crop quality in varieties used for fruit production.

Life cycle and taxonomy of Melampsora abietis-populi in China and its phylogenetic position in Melampsora on Populus

Rust diseases of Abies and Populus caused by Melampsora abietis-populi are observed in the forests of northeastern Asia. However, the life cycle and distribution of this species are not sufficiently clarified in China. The heteroecious life cycle alternating between spermogonial and aecial stages on A. holophylla and uredinial and telial stages on Populus pseudosimonii is confirmed for the first time in China by inoculations and phylogenetic analyses. The identity of these stages with M. abietis-populi is also confirmed by comparative morphology with specimens from Japan and phylogenetic analyses. These plants are new hosts for this species. Host plants and distribution of this species in China are described based on specimens obtained from the field and from inoculations. The phylogenetic position of this species within Melampsora is clarified for the first time. Based on morphological similarities and phylogenetic analyses, M. nujiangensis reported on Populus yunnanensis is treated as a synonym of M. abietis-populi.

Notes on rust fungi in China 9. Puccinia miscanthi life cycle and morphology confirmed by inoculation

The Heteroecious and macrocyclic life cycle of Puccinia miscanthi is confirmed for the first time with inoculation experiments in China. The rust produces spermogonial and aecial stages on Plantago asiatica and uredinial and telial stages on Miscanthus sacchariflorus. Morphological characters of these stages are described based on field collections and specimens that confirmed their life cycle connections. The neotype of P. miscanthi is designated.

Notes on rust fungi in China 8. Pucciniastrum tiliae life cycle and new host plants inferred from phylogenetic evidence

The life cycle connection between spermogonial and aecial stages of a rust fungus found on Abies holophylla and uredinial and telial stages on Tilia mongolica and T. mandshurica collected in northeast China were confirmed by phylogenetic analyses. The rust, identified as Pucciniastrum tiliae, was confirmed by morphological observations. The life cycle of this rust fungus is reported for the first time in China, and A. holophylla and T. mongolica represent new host plants for the species.

Identification of Berberis spp. as Alternate Hosts for Puccinia achnatheri-sibirici Under Controlled Conditions and Morphologic Observations of Sexual Stage Development of the Rust Fungus.

Gramineous grasses are a large group of species, many of which act as accessory (secondary) host for a large number of rust fungi, including devastating rust pathogens of cereals. Among the rust fungi, some are known to be heteroecious and have a complete macrocyclic life cycle with five types of spores on distinct plant species, but for many others the complete life cycle is unknown. Puccinia achnatheri-sibirici, a rust fungus infecting grasses in the genus Achnatherum, has been known for only its uredinial and telial stages; however, the other (pycnial and aecial) stages have not been identified. In this study, we demonstrate that P. achnatheri-sibirici is a heteroecious, macrocyclic fungus with the sexual stage on barberry (Berberis spp.) through inoculation. Pycnia and aecia were successively produced on the inoculated barberry plants. Inoculation of Achnatherum extremiorientale leaves with aeciospores produced yellow-orange uredinia with high infection types, whereas inoculation of wheat variety Mingxian 169, highly susceptible to Puccinia striiformis f. sp. tritici which causes stripe rust on wheat, produced chlorotic flecks but no uredinia. The ITS sequence analysis of P. achnatheri-sibirici did not match with any sequence in the NCBI database and had the highest homology with 94% compared to Puccinia brachypodii and Puccinia aizazii. Observations of the uredinial, telial, and basidial stages on A. extremiorientale and pycnial and aecial stages on Berberis shensiana using light and scanning electron microscopes revealed its characteristics. Morphological characteristics of urediniospores and teliospores are most similar with those of P. achnatheri-sibirici described in the literature. This study proved (1) the life cycle of P. achnatheri-sibirici as heteroecious and macrocyclic and the alternate host as barberry; (2) the description of life stages in the sexual cycle, especially the morphologies of aecial, pycnial, and basidial stages; and (3) the expansion of knowledge on the rust flora on barberry.