Erysiphe malvae Heluta

Zhang, Zhao-Yang, Wu, Xue-Lian, Lv, Xiao-Xue, Liu, Tie-Zhi, Jin, Dan-Ni, Liu, Li, Wang, Shuang-Bao, Feng, Jing, Hsiang, Tom, Li, Yu & Liu, Shu-Yan, 2025, Discover hidden taxa of Erysiphe section Erysiphe fungi (Ascomycota, Erysiphaceae) based on morphology and multilocus phylogeny in China, MycoKeys 118, pp. 119-146 : 119-146

Erysiphe malvae Heluta , Ukrayins’k. Bot. Zhurn. 47 (4): 75, 1990.

Fig. 7

Description.

Mycelium on leaves and stems, effuse or in irregular powdery layers, white, persistent; hyphae 3–8 μm wide; hyphal appressoria nipple-shaped to lobed. Asexual morph: Conidiophores erect, sometimes slightly flexuous, 62–116 (– 133) × 5–9 μm (without conidia), foot cells cylindrical, straight, 33–69 × 5–9 μm, followed by 1–2 cells, significantly shorter or longer than the foot cells, sometimes about as long as foot cells; conidia single, cylindrical, ellipsoid-cylindrical, 25–42 (– 46) × 12–18 μm, length / width ratio 1.6–4.0, colorless; the germ tube subterminal, medium length, club-shaped, apex simple or somewhat bent and swollen.

Host.

Malva pusilla ( Malvaceae ).

Distribution.

Asia ( China, Iran and Israel), Europe ( Ukraine).

Additional material examined.

China, Yunnan Prov. • 1; Kunming City ; 25°6'51"n, 102°45'9"e; ca. 1890 m a. s. l.; 26 Jun. 2019; Shu-Rong Tang & Jing Feng leg.; on M. pusilla ; HMJAU -PM 92233 . • 1; Kunming City ; 25°3'27"n, 102°41'55"e; alt. 1920 m a. s. l.; 27 Jun. 2019; Shu-Rong Tang & Jing Feng leg.; HMJAU -PM 92234 .

Notes.

Erysiphe malvae was initially described from Europe ( Ukraine) and subsequently documented in Asia ( Iran and Israel), with its most recent record in Nepal ( Adhikari 2021). This represents the first confirmed occurrence of this pathogen in China, where the specimen was collected in Yunnan Province in 2019. Morphological comparison of the Chinese anamorphs revealed fundamental congruence with the original description by Braun and Cook (2012), except for a discrepancy in subsequent cell count: our specimens exhibited 1–2 cells following the foot cells, compared to the 1–3 cells reported in the type description.

Sequence-based verification confirmed the taxonomic identity with E. malvae (on Malva pusilla ), with its phylogenetic position within the E. betae / E. heraclei / E. malvae complex clade (Figs 1 , 2 ).

Figures

Figure 1. Phylogenetic tree of selected species within sect. Erysiphe based on the ITS + 28 S regions. Bootstrap values greater than 60 % for the maximum likelihood (ML) analyses are displayed followed by posterior probabilities ≥ 0.70 of Bayesian inference (BI) analyses. HT = Holotype; the color box indicates new species; bold font indicates the new species obtained in this study; blue bold font indicates new record species.

Figure 2. Phylogenetic tree of selected species within sect. Erysiphe based on the ITS + 28 S + IGS + RPB 2 + TUB regions. Bootstrap values greater than 60 % for the maximum likelihood (ML) analyses are displayed followed by posterior probabilities ≥ 0.70 of Bayesian inference (BI) analyses. HT = Holotype; the color box indicates new species; bold font indicates the new species obtained in this study; blue bold font indicates new record species.

Figure 7. Symptoms and asexual morph of Erysiphe malvae on Malva pusilla (HMJAU - PM 92233) A, B powder layer on leaves C, D hyphal appressoria E – G conidiophores H – J conidia K, L germ tubes. Scale bars: 10 µm (C, D); 20 µm (E – L).