Gerwasia rubi-setchuenensis J. E. Sun, Yong Wang bis & K. D. Hyde, (2024)

Zhang, Qinfang, Wu, Qianzhen, Zhao, Peng, Habib, Kamran, Wang, Yao, Tang, Dexiang, Ahmad, Muhammad AIjaz, Ren, Yulin, Shen, Xiangchun, Long, Qingde, Liu, Lili & Li, Qirui, 2025, Unveiling new species of Phragmidiaceae (Basidiomycota, Pucciniales) on rosaceous plants from Guizhou, China, MycoKeys 115, pp. 309-326 : 309-326

Gerwasia rubi-setchuenensis J. E. Sun, Yong Wang bis & K. D. Hyde, (2024)

Fig. 5

Host.

Rubus buergeri Miq.

Description.

Spermogonia, aecia, and telia unknown. Uredinia 0.4–1.0 mm diam., hypophyllous, pulverulent, golden, scattered, irregular, surrounded by host epidermis. Urediniospores 24–30 × 19–25 µm (av. = 27.2 × 22.3 µm, n = 30), subglobose or fusiform, inclusions golden or bright yellow; wall 1.4–2.9 µm thick (av. = 2.0 μm, n = 30), colorless, irregularly elongated verrucae.

Materials examined.

China • Guizhou Province, Zunyi City , Xishui County (28°49'38"N, 106°41'23"E), 1223 m a. s. l., on the leaves of Rubus buergeri Miq. ( Rosaceae ), 3 November, 2022, Q. Z. Wu and Q. F. Zhang ( GMB 4052 ) ; China • Guizhou Province, Zunyi City , Xishui County (28°33'43"N, 106°24'3"E), 1997 m a. s. l., on Rubus buergeri ( Rosaceae ), 3 November 2022, Q. Z. Wu and Q. F. Zhang ( GMB 4075 ) .

Notes.

In the phylogram (Fig. 1 ), our collections ( GMB 4052 and GMB 4075 ) clustered with G. rubi-setchuenensis ( HGUP 21168 ). The morphological characteristics of our specimen are consistent with the original description of G. rubi-setchuenensis , and the DNA sequence aligns with that of G. rubi-setchuenensis HGUP 21168 (ITS 100 %; LSU 99.67 %) ( Sun et al. 2024). The only difference observed between the descriptions and figure of G. rubi-setchuenensis in Sun et al. (2024) is the size of the urediniospores. The urediniospores of G. rubi-setchuenensis ( GMB 4075 ) are slightly wider than those of G. rubi-setchuenensis ( HGUP 21168 ) (19–25 μm vs. 15–22 μm). This study identifies Rubus buergeri as a new host for this fungus.

Figures

Figure 1. RAxML tree of the family Phragmidiaceae based on rDNA ITS and LSU sequences. ML bootstrap supports (≥ 75 %) and Bayesian posterior probability (≥ 0.90) are indicated as ML / BYPP. The tree is rooted to G. sabinae and G. asiaticum (Yang et al. 2015; Aime et al. 2018). All species newly studied are indicated in red, with novel species highlighted in bold red. Type materials were highlighted in bold.

Figure 5. Gerwasia rubi-setchuenensis (GMB 4052) A – D host and its habitat E – F uredinia under the stereomicroscope G – K urediniospores. Scale bars: 0.5 mm (E – F); 10 μm (G – L).