About

Michael Bradshaw is an Assistant Professor in the Department of Entomology and Plant Pathology at NC State University. His research covers a wide spectrum of subjects within plant pathology, mycology, and evolution, with specialized expertise in taxonomy, population genetics, and disease control. Central to his work is the use of historical herbarium specimens to elucidate temporal and spatial movement patterns of emerging plant pathogens, with a primary focus on obligate pathogens such as powdery mildews. He employs a variety of methodological tools including fieldwork, laboratory experiments, greenhouse studies, herbarium specimen analysis, genetic sequencing, and bioinformatics. Additionally, his research explores the cultivation of fungi from understudied biomes and investigates fungicide resistance mechanisms at the genetic level.

Research topics

• Medicine
• Intensive care medicine
• Agronomy
• Pathology
• Biology
• Immunology
• Horticulture
• Veterinary medicine

Selected publications

• Podosphaera pannosa de Bary

  Open MIND · 2026-03-04

  articleOpen access

  Podosphaera pannosa (Wallr.) de Bary, Abh. Senkenb. Naturf. Ges. 7: 408, 1870. s. str. [emend] Fig. 7 ≡ Alphitomorpha pannosa Wallr., Verh. Ges. Naturf. Freunde Berlin 1: 43, 1819. ≡ Erysiphe pannosa (Wallr.) Link (as “ Erysibe ”), in Willdenow, Sp. pl., Edn 4, 6 (1): 104, 1824, nom. sanct. (Fr., Syst mycol. 3 (1): 236, 1829). ≡ Sphaerotheca pannosa (Wallr.) Lév., Ann. Sci. Nat., Bot., 3 Sér., 15: 138, 1851. Type. Neotype (designated here, MBT 10030088): Germany • Lower Saxony, Hannover-Ahlem, experimental section “ cemetery planting, ” on Rosa sp. cult. (hybrid), 27 Sep. 2018, P. Houska (NCSLG 24638). Isoneotype: HAL 3600 F. Ex-neotype sequences: PV 581762 (ITS + 28 S), PV 584310 (IGS), PV 584347 (TUB). Description. Mycelium on leaves, amphigenous, also on stems and petals, persistent, infected shoots often curled and distorted, forming irregular patches or effuse; primary hyphae hyaline, thin-walled, straight or sometimes flexuous, (2.5 –) 3–5.5 μm wide; secondary hyphae hyaline, thick-walled, 4–6 μm wide, colonies on twigs only developed in the later stages of the disease; hyphal appressoria indistinct to nipple-shaped, solitary or side by side; conidiophores arising from the upper surface of mother cells, erect, (52 –) 60–97 (– 99) × (6.5 –) 7.5–9.5 μm, foot cells straight, cylindrical, 33–59 × 7–9.5 μm, followed by (1 –) 2–3 shorter cells, forming catenescent conidia; conidia variable, primary conidia obovoid, secondary conidia doliiform to cylindrical, 20–26 × 11.5–15 μm, length / width ratio 1.5–2.1; germ tubes almost terminal. Chasmothecia gregarious, subglobose to globose, immersed in the secondary mycelial patches, mostly on stems, but also produced on leaves when the disease is severe, (74 –) 88–113 μm diam.; peridium cells round to irregularly polygonal, 4.0–16 μm diam.; appendages few, in the lower half of chasmothecia, mycelioid, short, usually shorter than chasmothecial diam., rarely up to 1.5 times diam., occasionally branching, brownish at the basal part or brown throughout, septate, thin-walled, smooth, coarse; ascus ovoid to fusiform, colorless, thick-walled, sessile or almost sessile, 87–140 × 63–84 μm, length / width ratio 1.2–1.9, terminal oculus obvious, large, 13.5–21 μm, 8 - spored; ascospores ellipsoid to round, colorless, (16.5 –) 18–25 × 12.5–17.5 μm, length / width ratio 1.1–1.9. Additional specimens examined. • A total of 51 specimens were examined, including 50 specimens with voucher numbers HMJAU -PM 92709 to HMJAU -PM 92758 and one specimen of HMAS 38723. Detailed specimen information is presented in Suppl. material 1. Host range and distribution. (phylogenetically confirmed hosts and distribution). Rosa (canina, chinensis, × damascena, foetida, gallica, laxa, majalis, multiflora, albertiirubiginosa, rugosa, xanthina), Prunus (armeniaca, cerasus, laurocerasus, persica, granatum), Rosaceae; Catharanthus roseus, Apocynaceae; Citrus reticulata × C. sinensis, Rutaceae; Corymbia citriodora, Eucalyptus (benthamii, grandis, sp.), Myrtaceae; and Forsythia × intermedia, Oleaceae. Asia (China, India, Iraq, Israel, Japan, Pakistan, South Korea, Vietnam), Europe (Belgium, France, Germany, Netherlands, Serbia, Spain, United Kingdom), North America (Mexico, United States), Oceania (Australia, New Zealand), and South America (Argentina, Brazil, Chile, Peru, Uruguay). Notes. Podosphaera pannosa is the most widely distributed species on Rosa spp. Alphitomorpha pannosa, the basionym, was described from Germany, but type material is not preserved (Braun and Cook 2012). Therefore, a German specimen is designated as the neotype with ex-neotype ITS, 28 S, IGS, and TUB sequences. Based on the current morphological and phylogenetic results, it is clear that P. rosae is genetically distinguishable from P. pannosa. The records of P. pannosa on R. rugosa (HMAS 01630, 14132) in Zheng and Yu (1987) from China should probably be revised to P. rosae after re-examining the specimens. The description and illustration of P. pannosa in Shin (2000) from Korea are also more in line with P. rosae and in need of revision. There are numerous morphological descriptions of P. pannosa that appear to be composed of characteristics of both P. pannosa and P. rosae (Braun 1987, 1995; Liu 2010; Braun and Cook 2012). The confusions and misidentifications were documented as early as Salmon’s monograph (1900). He postulated that the primary reason for this confusion was the erroneous assumption that the species of fungus that occurs on a certain host plant in one part of the world will be the same as that growing on the same host in other parts of the world. As such, many powdery mildews on Rosa spp. were identified as P. pannosa, and the other possible species were ignored. In addition, the chasmothecia of P. pannosa are rarely formed (Salmon 1900; Blumer 1933; Homma 1937; Junell 1967; Nomura 1997), so the fact that chasmothecia of P. rosae appear to be more common than those of P. pannosa may be another reason for the confusion. To our knowledge, P. rosae often forms chasmothecia in China in late autumn when the temperature decreases. Chasmothecia of P. pannosa are rarely formed, even when chasmothecia of P. rosae are formed at the same time and place. The chasmothecia of P. pannosa can be found in winter or even the following spring, and they are primarily formed on stems, rarely on leaves, with abundant secondary mycelium. The more frequently produced chasmothecia of P. rosae are undoubtedly the reason that they have often erroneously been assigned to P. pannosa, at least before these two species were separated. Consequently, on account of the persistent taxonomic confusion between these two species, the distribution and host range require further clarification. In this study, host range and distribution are listed based on the results of the phylogenetic analysis (see Fig. 3).

  PublisherDOI

• Podosphaera pannosa de Bary

  Zenodo (CERN European Organization for Nuclear Research) · 2026-03-04

  articleOpen access

  Podosphaera pannosa (Wallr.) de Bary, Abh. Senkenb. Naturf. Ges. 7: 408, 1870. s. str. [emend] Fig. 7 ≡ Alphitomorpha pannosa Wallr., Verh. Ges. Naturf. Freunde Berlin 1: 43, 1819. ≡ Erysiphe pannosa (Wallr.) Link (as “ Erysibe ”), in Willdenow, Sp. pl., Edn 4, 6 (1): 104, 1824, nom. sanct. (Fr., Syst mycol. 3 (1): 236, 1829). ≡ Sphaerotheca pannosa (Wallr.) Lév., Ann. Sci. Nat., Bot., 3 Sér., 15: 138, 1851. Type. Neotype (designated here, MBT 10030088): Germany • Lower Saxony, Hannover-Ahlem, experimental section “ cemetery planting, ” on Rosa sp. cult. (hybrid), 27 Sep. 2018, P. Houska (NCSLG 24638). Isoneotype: HAL 3600 F. Ex-neotype sequences: PV 581762 (ITS + 28 S), PV 584310 (IGS), PV 584347 (TUB). Description. Mycelium on leaves, amphigenous, also on stems and petals, persistent, infected shoots often curled and distorted, forming irregular patches or effuse; primary hyphae hyaline, thin-walled, straight or sometimes flexuous, (2.5 –) 3–5.5 μm wide; secondary hyphae hyaline, thick-walled, 4–6 μm wide, colonies on twigs only developed in the later stages of the disease; hyphal appressoria indistinct to nipple-shaped, solitary or side by side; conidiophores arising from the upper surface of mother cells, erect, (52 –) 60–97 (– 99) × (6.5 –) 7.5–9.5 μm, foot cells straight, cylindrical, 33–59 × 7–9.5 μm, followed by (1 –) 2–3 shorter cells, forming catenescent conidia; conidia variable, primary conidia obovoid, secondary conidia doliiform to cylindrical, 20–26 × 11.5–15 μm, length / width ratio 1.5–2.1; germ tubes almost terminal. Chasmothecia gregarious, subglobose to globose, immersed in the secondary mycelial patches, mostly on stems, but also produced on leaves when the disease is severe, (74 –) 88–113 μm diam.; peridium cells round to irregularly polygonal, 4.0–16 μm diam.; appendages few, in the lower half of chasmothecia, mycelioid, short, usually shorter than chasmothecial diam., rarely up to 1.5 times diam., occasionally branching, brownish at the basal part or brown throughout, septate, thin-walled, smooth, coarse; ascus ovoid to fusiform, colorless, thick-walled, sessile or almost sessile, 87–140 × 63–84 μm, length / width ratio 1.2–1.9, terminal oculus obvious, large, 13.5–21 μm, 8 - spored; ascospores ellipsoid to round, colorless, (16.5 –) 18–25 × 12.5–17.5 μm, length / width ratio 1.1–1.9. Additional specimens examined. • A total of 51 specimens were examined, including 50 specimens with voucher numbers HMJAU -PM 92709 to HMJAU -PM 92758 and one specimen of HMAS 38723. Detailed specimen information is presented in Suppl. material 1. Host range and distribution. (phylogenetically confirmed hosts and distribution). Rosa (canina, chinensis, × damascena, foetida, gallica, laxa, majalis, multiflora, albertiirubiginosa, rugosa, xanthina), Prunus (armeniaca, cerasus, laurocerasus, persica, granatum), Rosaceae; Catharanthus roseus, Apocynaceae; Citrus reticulata × C. sinensis, Rutaceae; Corymbia citriodora, Eucalyptus (benthamii, grandis, sp.), Myrtaceae; and Forsythia × intermedia, Oleaceae. Asia (China, India, Iraq, Israel, Japan, Pakistan, South Korea, Vietnam), Europe (Belgium, France, Germany, Netherlands, Serbia, Spain, United Kingdom), North America (Mexico, United States), Oceania (Australia, New Zealand), and South America (Argentina, Brazil, Chile, Peru, Uruguay). Notes. Podosphaera pannosa is the most widely distributed species on Rosa spp. Alphitomorpha pannosa, the basionym, was described from Germany, but type material is not preserved (Braun and Cook 2012). Therefore, a German specimen is designated as the neotype with ex-neotype ITS, 28 S, IGS, and TUB sequences. Based on the current morphological and phylogenetic results, it is clear that P. rosae is genetically distinguishable from P. pannosa. The records of P. pannosa on R. rugosa (HMAS 01630, 14132) in Zheng and Yu (1987) from China should probably be revised to P. rosae after re-examining the specimens. The description and illustration of P. pannosa in Shin (2000) from Korea are also more in line with P. rosae and in need of revision. There are numerous morphological descriptions of P. pannosa that appear to be composed of characteristics of both P. pannosa and P. rosae (Braun 1987, 1995; Liu 2010; Braun and Cook 2012). The confusions and misidentifications were documented as early as Salmon’s monograph (1900). He postulated that the primary reason for this confusion was the erroneous assumption that the species of fungus that occurs on a certain host plant in one part of the world will be the same as that growing on the same host in other parts of the world. As such, many powdery mildews on Rosa spp. were identified as P. pannosa, and the other possible species were ignored. In addition, the chasmothecia of P. pannosa are rarely formed (Salmon 1900; Blumer 1933; Homma 1937; Junell 1967; Nomura 1997), so the fact that chasmothecia of P. rosae appear to be more common than those of P. pannosa may be another reason for the confusion. To our knowledge, P. rosae often forms chasmothecia in China in late autumn when the temperature decreases. Chasmothecia of P. pannosa are rarely formed, even when chasmothecia of P. rosae are formed at the same time and place. The chasmothecia of P. pannosa can be found in winter or even the following spring, and they are primarily formed on stems, rarely on leaves, with abundant secondary mycelium. The more frequently produced chasmothecia of P. rosae are undoubtedly the reason that they have often erroneously been assigned to P. pannosa, at least before these two species were separated. Consequently, on account of the persistent taxonomic confusion between these two species, the distribution and host range require further clarification. In this study, host range and distribution are listed based on the results of the phylogenetic analysis (see Fig. 3).

  PublisherDOI

• Erysiphe simulans U. Braun & S. Takam.

  Open MIND · 2026-03-04

  articleOpen access

  Erysiphe simulans (E. S. Salmon) U. Braun & S. Takam., Schlechtendalia 4: 23, 2000 Figs 5, 6 ≡ Uncinula simulans E. S. Salmon, Ann. Mycol. 6: 2, 1908. ≡ Uncinuliella simulans (E. S. Salmon) R. Y. Zheng & G. Q. Chen, Acta Microbiol. Sin. 19 (3): 286, 1979. = Uncinuliella simulans var. rosae-rubi R. Y. Zheng & G. Q. Chen, Acta Microbiol. Sin. 19 (3): 288, 1979. ≡ Erysiphe simulans var. rosae-rubi (R. Y. Zheng & G. Q. Chen) U. Braun & S. Takam., Schlechtendalia 4: 23, 2000. = Uncinuliella simulans var. tandae U. Braun, Mycotaxon 22 (1): 92, 1985. ≡ Erysiphe simulans var. tandae (U. Braun) U. Braun & S. Takam., Schlechtendalia 4: 24, 2000. Type. Lectotype (designated by Braun 1987): Japan • Morioka, on Rosa multiflora, 21 Oct. 1906, Sawada (TNS-F-214613). Reference sequences (designated by Bradshaw et al. 2023): AB 015926 (ITS), AB 022395 (28 S) [in Takamatsu et al. (1999) and Mori et al. (2000)]. Specimens examined. • A total of 13 specimens were examined, including HMJAU -PM 92698 to HMJAU -PM 92708, and two specimens from the Herbarium Mycologicum Academiae Sinicae, HMAS 11418 and HMAS 13631. Detailed specimen information is presented in Suppl. material 1. Morphological description. Braun and Cook (2012: 586). Host range and distribution. on Rosa (multiflora, odorata, rubus), Rosaceae; Asia (China, Japan, Korea). Notes. Bradshaw et al. (2023) found that the sequences of E. simulans var. rosae-rubi and E. simulans var. tandae grouped together with high bootstrap values. The authors reported that the morphological differences were only gradual or had overlapping quantitative features and, as such, concluded that varieties under E. simulans should be discarded. The morphology of a reference specimen of E. simulans from Japan (HMAS 13631) and the holotype of E. simulans var. rosae-rubi from China (HMAS 11418) were re-examined in this study (Figs 5, 6). We confirmed that the two are highly similar in all characteristics. The differences in the number of appendages described by Zheng and Chen (1979) are also indistinct and overlap with each other. Although we failed to amplify sequences from those two specimens, other sequences of E. simulans were obtained from eleven newly collected specimens. The present phylogenetic analysis showed that there are minimal genetic differences within this species. Therefore, it is reasonable and justified to discard these varieties of E. simulans.

  PublisherDOI

• Erysiphe rosae D. - N. Jin & S. - Y. Liu 2026

  Zenodo (CERN European Organization for Nuclear Research) · 2026-03-04

  articleOpen access

  Erysiphe rosae (Golovin & Gamalitsk.) U. Braun & S. Takam., Schlechtendalia 4: 4, 2000 Fig. 4 ≡ Medusosphaera rosae Golovin & Gamalitsk., Bot. Mater. Otd. Sporov. Rast. Bot. Inst. Komarova Akad. Nauk S. S. S. R. 15: 92, 1962. Type. Holotype: Kyrgyzstan • Tjan-Shan, Kavak-Tau, Tabylgyty, on Rosa albertii, 14 Sep. 1959, Gamalitskaya (LE 193792). Reference collection: China, Xinjiang, Urumqi, on Rosa albertii, 3 Aug. 2009, Z. Y. Zhao & B. Xu (HMAS 242383). Reference sequences: PX 506005 (ITS), PX 506007 (28 S), PX 570626 (IGS). Specimens examined. • HMJAU -PM 92697, HMAS 36517, HMAS 36518, HMAS 44287, and HMAS 138804. Detailed specimen information is presented in Suppl. material 1. Morphological description. Braun and Cook (2012: 501–502). Host range and distribution. on Rosa (albertii, amblyotis, davurica, omeiensis, webbiana), Rosaceae; Asia (China, India, Kyrgyzstan, Russia, Far East). Notes. Erysiphe rosae is characterized by sinuous long appendages and bristle-like short appendages. This taxon has been controversially treated at the generic level. It was first introduced as the type species of the genus Medusosphaera and later transferred to Erysiphe because the morphology of the chasmothecial appendages was no longer recognized as suitable for differentiation at the generic level (Golovin and Gamalitskaya 1962; Braun and Takamatsu 2000). The correct allocation of M. rosae to Erysiphe was confirmed in the present study based on lobed hyphal appressoria and conidiophores with singly formed conidia (Fig. 4), as well as sequences successfully retrieved from specimens of this species, which form a highly supported species clade within Erysiphe (Fig. 1). It should be noted that the sequences of the three examined specimens clustered together according to their host plants, which indicates previously unrecognized diversity within E. rosae, possibly suggesting cryptic formae, a taxonomic unit recently reapplied in Erysiphaceae (Bradshaw et al. 2025 c; Feng et al. 2025 a). However, due to the limited number of specimens available, it was impossible to obtain additional molecular data or to observe potential morphological differences. Therefore, following the species concept proposed by Bradshaw et al. (2022), we provisionally treated these specimens as E. rosae s. lat. Since the holotype of this species from Kyrgyzstan has not yet been sequenced, the Chinese specimen HMAS 242383 on the type host Rosa albertii is selected as the reference collection with reference sequences for the interim.

  PublisherDOI

• Reassessment of the Erysiphe aquilegiae complex (Erysiphaceae)—resolution of a widespread and economically significant group of plant pathogens

  Fungal Biology · 2026-01-09

  articleOpen access1st authorCorresponding

  Species of powdery mildew in the Erysiphe aquilegiae complex infect a broad array of economically valuable plants. The increasing number of reports of infections from diverse hosts prompted the present comprehensive phylogenetic and taxonomic reassessment of the complex. Accurate species delimitation within the complex has been hindered by morphological similarity among members of the complex, their broad host associations, and insufficient resolution in rDNA (ITS+28S) analyses. As such, the species concepts within this complex have been controversial, ranging from recognition of a single widely circumscribed species, E. aquilegiae s. lat., to narrower concepts recognizing multiple species, usually based on associated host genera or host species. To better understand this complex, we have undertaken phylogenetic analyses based on eight loci: rDNA regions (ITS, 28S, IGS) and protein-coding genes (CAM, GAPDH, GS, RPB2, TUB). In total, we sequenced 163 collections from more than 20 countries, resulting in the deposition of over 600 sequences in GenBank. Based on these results, we have recognized two species with broad host ranges, E. aquilegiae s. str. (emend.) and E. hortensiae comb. nov., There are several host-specific species, including: E. aquilegiae-coeruleae sp. nov. E. clematidicola sp. nov. E. clematidis-montanae sp. nov., and E. thalictri sp. nov. The old name E. nitida is reintroduced for powdery mildew on Aconitum spp. and Delphinium spp. (Ranunculaceae tribe Delphinieae), which forms a well-supported clade outside the E. aquilegiae s. str. and E. hortensiae clade. Furthermore, E. parnassiae could be confirmed as a separate species belonging to the E. aquilegiae complex. The application of the rank forma for genetically established biological races forming subclades within the plurivorous species is discussed and conditions for the introduction of acceptable formae are outlined.

  PublisherDOI

• Revision of powdery mildews (Ascomycota, Erysiphaceae) on Rosa in China: unexpected taxonomic complexity with phytopathological implications

  Open MIND · 2026-03-04

  dataset

  This dataset contains the digitized treatments in Plazi based on the original journal article Jin, Dan-Ni, Wang, Shuang-Bao, Guan, Le-Ping, Wu, Xue-Lian, Feng, Jing, Liu, Li, Bradshaw, Michael, Braun, Uwe, Yang, Jing-Han, Yu, Shou-Rong, Li, Yu, Liu, Shu-Yan (2026): Revision of powdery mildews (Ascomycota, Erysiphaceae) on Rosa in China: unexpected taxonomic complexity with phytopathological implications. IMA Fungus 17: e 184484, DOI: 10.3897/imafungus.17.184484AbstractPowdery mildew is a persistent disease affecting the cultivation of Rosa, a genus of substantial horticultural and economic value worldwide. Despite more than a century of study, the true diversity of powdery mildews infecting roses has remained unclear, largely due to the long-standing and overly broad application of the name Podosphaera pannosa. To reassess this system, we conducted an extensive investigation of powdery mildew specimens infecting Rosa. A total of 112 collections were examined, including recently gathered material from 23 provinces, historical types, representative specimens from the Herbarium Mycologicum Academiae Sinicae (HMAS), China, and a neotype specimen from Germany. Morphological observations combined with phylogenetic analyses (ITS, 28 S, and IGS rDNA) resolved several long-standing taxonomic problems and revealed unexpected diversity within the rose powdery mildew complex. Molecular data from Erysiphe rosae provide the first phylogenetic evidence supporting the synonymy of Medusosphaera with Erysiphe. Sphaerotheca rosae, previously treated as a synonym of P. pannosa, is reinstated as a distinct species as Podosphaera rosae comb. nov., and a previously unrecognized lineage is described as Podosphaera rosae-xanthinae sp. nov. In addition, earlier varieties of E. simulans are shown to lack diagnostic morphological or genetic characters and are no longer supported. Taken together, these results demonstrate that powdery mildews on Rosa represent a complex of five species across two genera, structured by host phylogeny. Clear patterns of host preference and distribution indicate a history of co-evolution and ecological differentiation driven by host availability. This study fundamentally revises our understanding of rose powdery mildews, revealing a level of taxonomic and evolutionary complexity much greater than previously recognized and highlighting Rosa as a key host lineage in the diversification of the Erysiphaceae.

  DOI

• Hidden treasures of herbaria - even small collections contain a wealth of diversity: the powdery mildews of the North Carolina State Larry F. Grand Mycological Herbarium

  The Catalogue of Life · 2026-02-16

  datasetOpen accessSenior author
  PublisherDOI

• Erysiphe simulans U. Braun & S. Takam.

  Zenodo (CERN European Organization for Nuclear Research) · 2026-03-04

  articleOpen access

  Erysiphe simulans (E. S. Salmon) U. Braun & S. Takam., Schlechtendalia 4: 23, 2000 Figs 5, 6 ≡ Uncinula simulans E. S. Salmon, Ann. Mycol. 6: 2, 1908. ≡ Uncinuliella simulans (E. S. Salmon) R. Y. Zheng & G. Q. Chen, Acta Microbiol. Sin. 19 (3): 286, 1979. = Uncinuliella simulans var. rosae-rubi R. Y. Zheng & G. Q. Chen, Acta Microbiol. Sin. 19 (3): 288, 1979. ≡ Erysiphe simulans var. rosae-rubi (R. Y. Zheng & G. Q. Chen) U. Braun & S. Takam., Schlechtendalia 4: 23, 2000. = Uncinuliella simulans var. tandae U. Braun, Mycotaxon 22 (1): 92, 1985. ≡ Erysiphe simulans var. tandae (U. Braun) U. Braun & S. Takam., Schlechtendalia 4: 24, 2000. Type. Lectotype (designated by Braun 1987): Japan • Morioka, on Rosa multiflora, 21 Oct. 1906, Sawada (TNS-F-214613). Reference sequences (designated by Bradshaw et al. 2023): AB 015926 (ITS), AB 022395 (28 S) [in Takamatsu et al. (1999) and Mori et al. (2000)]. Specimens examined. • A total of 13 specimens were examined, including HMJAU -PM 92698 to HMJAU -PM 92708, and two specimens from the Herbarium Mycologicum Academiae Sinicae, HMAS 11418 and HMAS 13631. Detailed specimen information is presented in Suppl. material 1. Morphological description. Braun and Cook (2012: 586). Host range and distribution. on Rosa (multiflora, odorata, rubus), Rosaceae; Asia (China, Japan, Korea). Notes. Bradshaw et al. (2023) found that the sequences of E. simulans var. rosae-rubi and E. simulans var. tandae grouped together with high bootstrap values. The authors reported that the morphological differences were only gradual or had overlapping quantitative features and, as such, concluded that varieties under E. simulans should be discarded. The morphology of a reference specimen of E. simulans from Japan (HMAS 13631) and the holotype of E. simulans var. rosae-rubi from China (HMAS 11418) were re-examined in this study (Figs 5, 6). We confirmed that the two are highly similar in all characteristics. The differences in the number of appendages described by Zheng and Chen (1979) are also indistinct and overlap with each other. Although we failed to amplify sequences from those two specimens, other sequences of E. simulans were obtained from eleven newly collected specimens. The present phylogenetic analysis showed that there are minimal genetic differences within this species. Therefore, it is reasonable and justified to discard these varieties of E. simulans.

  PublisherDOI

• Podosphaera rosae-xanthinae D. - N. Jin & S. - Y. Liu 2026, sp. nov.

  Open MIND · 2026-03-04

  articleOpen access

  Podosphaera rosae-xanthinae D. - N. Jin & S. - Y. Liu sp. nov. Fig. 9 Etymology. Epithet derived from the name of the type host species, Rosa xanthina. Type. Holotype: China • Jilin, Changchun, on Rosa xanthina, 8 Aug. 2023, D. N. Jin & X. L. Wu (HMJAU -PM 92790). Ex-holotype sequences: PX 239433 (ITS), PX 239312 (28 S), PX 239920 (IGS). Isotype: HMAS 354228. Diagnosis. Close to Podosphaera pannosa, but differing in having shorter conidiophores and smaller asci, and forming a separate well-supported species clade in the phylogenetic analysis. Description. Mycelium on stems and both sides of leaves, more abundant on the lower surface of the leaves, forming irregular patches or effuse, persistent, infected shoots often curled and distorted, primary mycelium white, secondary mycelium in dense, pannose patches on the stems; primary hyphae hyaline, thin-walled, 2.5–5 μm wide, secondary hyphae hyaline, thick-walled, 3.5–5.5 μm wide, sparsely branched; hyphal appressoria indistinct to nipple-shaped, solitary or side by side; conidiophores arising from the upper surface of mother cells, erect, 48–91 (– 96) × 7–9.5 μm, foot cells straight, cylindrical, (24 –) 26–56 (– 61) × 6.5–9.5 μm, followed by 2–3 shorter cells, forming catenescent conidia; primary conidia obovoid, secondary conidia doliiform to ellipsoid, 18.5–25 × 11–14.5 μm, length / width ratio 1.4–1.9; germ tubes almost terminal to almost lateral, short. Chasmothecia gregarious, subglobose to globose, immersed in the secondary mycelial patches, mostly on the stems, (71 –) 73–96 μm diam.; peridium cells round to irregularly shaped, 5–21 (– 26) μm diam.; appendages mycelioid, simple, short, arising from the lower half of chasmothecia, usually curved, hyaline throughout or light brown below, paler towards the apex, septate, variable in length, usually 0.2–1 times as long as the chasmothecial diam.; ascus ovoid to ellipsoid, colorless, thick-walled, sessile or short-stalked, 73–102 × 57–71 (– 75) μm, length / width ratio 1.2–1.6, terminal oculus inconspicuous to distinct, (11 –) 14–26 μm, 8 - spored; ascospores ellipsoid – ovoid, colorless, 23–28 × 15.5–18.5 μm, length / width ratio 1.4–1.7. Additional specimens examined. • A total of eight specimens were examined under the vouchers from HMJAU -PM 92786 to HMJAU -PM 92793. Detailed specimen information is presented in Suppl. material 1. Host range and distribution. on Rosa (xanthina), Rosaceae; Asia (China). Notes. Asexual powdery mildew morphs are common on Rosa xanthina. The conidiophores and foot cells are usually shorter than those in Podosphaera pannosa. Conidia are also smaller, and the length / width ratio is always less than 2. Chasmothecia are usually formed and are immersed in secondary mycelial patches on twigs in late autumn or early winter. The teleomorph of powdery mildew on Rosa xanthina is similar to P. pannosa, but differs in having broader asci, sometimes with stalks. Sequences of the powdery mildew on R. xanthina form a well-supported, separate species clade in phylogenetic analyses. As a result, a new species, P. rosae-xanthinae, is described, which is so far known only on R. xanthina.

  PublisherDOI

• Podosphaera rosae-xanthinae D. - N. Jin & S. - Y. Liu 2026, sp. nov.

  Zenodo (CERN European Organization for Nuclear Research) · 2026-03-04

  articleOpen access

  Podosphaera rosae-xanthinae D. - N. Jin & S. - Y. Liu sp. nov. Fig. 9 Etymology. Epithet derived from the name of the type host species, Rosa xanthina. Type. Holotype: China • Jilin, Changchun, on Rosa xanthina, 8 Aug. 2023, D. N. Jin & X. L. Wu (HMJAU -PM 92790). Ex-holotype sequences: PX 239433 (ITS), PX 239312 (28 S), PX 239920 (IGS). Isotype: HMAS 354228. Diagnosis. Close to Podosphaera pannosa, but differing in having shorter conidiophores and smaller asci, and forming a separate well-supported species clade in the phylogenetic analysis. Description. Mycelium on stems and both sides of leaves, more abundant on the lower surface of the leaves, forming irregular patches or effuse, persistent, infected shoots often curled and distorted, primary mycelium white, secondary mycelium in dense, pannose patches on the stems; primary hyphae hyaline, thin-walled, 2.5–5 μm wide, secondary hyphae hyaline, thick-walled, 3.5–5.5 μm wide, sparsely branched; hyphal appressoria indistinct to nipple-shaped, solitary or side by side; conidiophores arising from the upper surface of mother cells, erect, 48–91 (– 96) × 7–9.5 μm, foot cells straight, cylindrical, (24 –) 26–56 (– 61) × 6.5–9.5 μm, followed by 2–3 shorter cells, forming catenescent conidia; primary conidia obovoid, secondary conidia doliiform to ellipsoid, 18.5–25 × 11–14.5 μm, length / width ratio 1.4–1.9; germ tubes almost terminal to almost lateral, short. Chasmothecia gregarious, subglobose to globose, immersed in the secondary mycelial patches, mostly on the stems, (71 –) 73–96 μm diam.; peridium cells round to irregularly shaped, 5–21 (– 26) μm diam.; appendages mycelioid, simple, short, arising from the lower half of chasmothecia, usually curved, hyaline throughout or light brown below, paler towards the apex, septate, variable in length, usually 0.2–1 times as long as the chasmothecial diam.; ascus ovoid to ellipsoid, colorless, thick-walled, sessile or short-stalked, 73–102 × 57–71 (– 75) μm, length / width ratio 1.2–1.6, terminal oculus inconspicuous to distinct, (11 –) 14–26 μm, 8 - spored; ascospores ellipsoid – ovoid, colorless, 23–28 × 15.5–18.5 μm, length / width ratio 1.4–1.7. Additional specimens examined. • A total of eight specimens were examined under the vouchers from HMJAU -PM 92786 to HMJAU -PM 92793. Detailed specimen information is presented in Suppl. material 1. Host range and distribution. on Rosa (xanthina), Rosaceae; Asia (China). Notes. Asexual powdery mildew morphs are common on Rosa xanthina. The conidiophores and foot cells are usually shorter than those in Podosphaera pannosa. Conidia are also smaller, and the length / width ratio is always less than 2. Chasmothecia are usually formed and are immersed in secondary mycelial patches on twigs in late autumn or early winter. The teleomorph of powdery mildew on Rosa xanthina is similar to P. pannosa, but differs in having broader asci, sometimes with stalks. Sequences of the powdery mildew on R. xanthina form a well-supported, separate species clade in phylogenetic analyses. As a result, a new species, P. rosae-xanthinae, is described, which is so far known only on R. xanthina.

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Recent grants

• ARTS: A North American monograph of the powdery mildews (Erysiphaceae)

  NSF · $1.0M · 2023–2023

Frequent coauthors

• Siddharama Pawate

  235 shared

• Ilya Kister

  NYU Langone Health

  159 shared

• Tanuja Chitnis

  Massachusetts General Hospital

  142 shared

• Daniel Kantor

  122 shared

• Maya Zeineddine

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• Keith R. Edwards

  University of South Bohemia in České Budějovice

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• Danita VanderKodde

  Tidewater Community College

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• Erin E. Longbrake

  Yale University

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Education

• PhD, Environmental and Forest Science

  University of Washington

  2020