Cytospora fengtaiensis A.L. Jia & X.L. Fan, 2024

Jia, Aoli, Chen, Baoyue, Lu, Hongyan, Xing, Yu, Li, Bin & Fan, Xinlei, 2024, Multigene phylogeny and morphology reveal three new species of Cytospora isolated from diseased plant branches in Fengtai District, Beijing, China, MycoKeys 101, pp. 163-189 : 163

Cytospora fengtaiensis A.L. Jia & X.L. Fan sp. nov.

Fig. 6

Etymology.

Named after the place where it was first collected, Fengtai District, Beijing City.

Typification.

China. Beijing City, Fengtai District, Qianling Mountain scenic area, 39°51'12.28"N, 116°5'17.74"E, from branches of Acer palmatum ' Atropurpureum ', 7 Apr 2023, A.L. Jia & X.L. Fan (holotype BJFC CF20230405, ex-holotype living culture CFCC 59449); 39°51'12.51"N, 116°5'17.32"E, from branches of Acer palmatum ' Atropurpureum ', 7 Apr 2023, A.L. Jia & X.L. Fan (paratype BJFC CF20230406, ex-paratype living culture CFCC 59442.

Description.

Sexual morph: not observed. Asexual morph: Conidiomata pycnidial, immersed in the bark, scattered, producing black area on bark, circular to ovoid, with multiple locules, occasionally slightly erumpent through the surface. Conceptacle absent. Ectostromatic disc conspicuous, grey to black, discoid, circular to ovoid, 180-250 µm in diam., producing one ostiole per disc when mature. Ostiole grey to black, nearly at the same level as the disc surface, 70-105 µm in diam. Locules numerous, subdivided frequently by invaginations with common walls, circular to ovoid, 560-800 µm in diam. Conidiophores hyaline, unbranched, approximately cylindrical, 11-17 × 1.5-2 (av. = 14.7 ± 2.7 × 1.6 ± 0.3, n = 50) µm. Conidiogenous cells enteroblastic, phialidic. Conidia hyaline, elongate-allantoid, smooth, aseptate, 5-6 × 1-2 (av. = 5.5 ± 0.5 × 1.6 ± 0.2, n = 50) µm.

Culture characteristics.

Cultures on PDA are initially white to pale vinaceous, growing slowly up to 3 cm after 3 d and entirely covering the 6 cm Petri dish after 7 d, becoming fawn after 14 d. Colonies are flat with a uniform texture, Colony margin irregular. After 30 d, pycnidia aggregated on surface.

Additional materials examined.

China. Beijing City, Fengtai District, Qianling Mountain scenic area, 39°51'11.45"N, 116°5'15.36"E, from branches of Acer palmatum ' Atropurpureum ', 7 Apr 2023, A.L. Jia & X.L. Fan (BJFC CF20230407, living culture CFCC 59525; BJFC CF20230408, living cultures CFCC 59526 and 59527) .

Notes.

Cytospora fengtaiensis is associated with canker disease of Acer palmatum ' Atropurpureum ' in the current study. It can be identified by its conidiomata producing larger black areas on bark. Phylogenetically, five isolates in this study formed a distinct lineage in the phylogenetic trees of each individual gene (ITS, act, rpb2, tef1-α and tub2) and the combined gene dataset (Fig. 2 ).

Figures

Figure 2. Phylogram of Cytospora based on Maximum Likelihood (ML) analysis of the dataset of combined ITS, act, rpb 2, tef 1 - a and tub 2 genes. Numbers above the branches indicate ML bootstrap values (ML-BS ≥ 60 %) and Bayesian Posterior Probabilities (BPP ≥ 0.9). Ex-type isolates are in bold. lsolates in this study marked with its hosts and highlighted in two different colours where the novel species are shown in dark blue and the known species are shown in light blue.

Figure 6. Cytospora fengtaiensis from Acer palmatum ' Atropurpureum ' (BJFC CF 20230405) A, B habit of conidiomata on branch C transverse section through conidiomata D longitudinal section through conidiomata E conidiophores and conidiogenous cells F conidia. Scale bars: 1 mm (A); 200 µm (B-D); 10 µm (E, F).