Diaporthe changpingensis Y.K. Bai & X.L. Fan, 2023

Bai, Yukun, Lin, Lu, Pan, Meng & Fan, Xinlei, 2023, Studies of Diaporthe (Diaporthaceae, Diaporthales) species associated with plant cankers in Beijing, China, with three new species described, MycoKeys 98, pp. 59-86 : 59

Diaporthe changpingensis Y.K. Bai & X.L. Fan sp. nov.

Fig. 2

Etymology.

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

Description.

Sexual morph not observed. Asexual morph: Conidiomata pycnidial, conical, immersed in bark, scattered, erumpent through the surface, with a solitary locule. Locule undivided, 620-830 μm diam. Conidiophores cylindrical, attenuate towards the apex, hyaline, phialidic, unbranched, slightly curved, 8.5-12.5 × 1.0-2.0 μm (av. = 10 ± 1.3 × 1.6 ± 0.3 μm, n = 50). Conidiogenous cells enteroblastic, phialidic, subcylindrical to cylindrical, 6.5-9.5 × 1.0-2.0 µm (av. = 8.0 ± 1.1 × 1.7 ± 0.2 µm, n = 50). Alpha conidia hyaline, aseptate, fusiform to oval, multi-guttulate, acute at both ends, 5.5-9.0 × 1.5-3.0 μm (av. = 6.5 ± 0.7 × 2.1 ± 0.5 μm, n = 50), L/W = 3.0-4.0 (av. = 3.5 ± 0.3, n = 50). Beta conidia hyaline, aseptate, filiform, straight or hamate, eguttulate, 13.0-19.0 × 1.0-2.0 μm (av. = 15.5 ± 1.5 × 1.5 ± 0.3 μm, n = 50), L/W = 9-11 (av. = 10 ± 0.4, n = 50).

Culture characteristics.

Cultures on PDA initially white, growing slowly and entirely covering the 9 cm Petri dish after 14 days. The colonies flat, lacking aerial mycelium with an irregular edge. Conidiomata not observed on medium surface until 30 days.

Specimens examined.

China, Beijing City, Changping District, Baihujian Forest Park , 40°7'34.15"N, 116°5'30.26"E, on twigs and branches of Robinia pseudoacacia , 20 Aug 2022, Y.K. Bai, L. Lin & M. Pan (holotype BJFC CF202212141, ex-type living culture: CFCC 58812; other living culture: CFCC 58813) .

Notes.

Diaporthe changpingensis was isolated from Robinia pseudoacacia . The molecular phylogenies of this species show a clearly different position in this study with high support (ML/BI = 100/1.00). This species appears most closely related to D. canthii . However, D. changpingensis can be distinguished from D. canthii , based on ITS, tef1-α and tub2 loci (23/458 in ITS, 38/326 in tef1-α and 31/417 in tub2). Morphologically, D. changpingensis differs from D. canthii in having shorter alpha conidia (5.5-9.0 vs. 12.0-14.0 μm) and shorter beta conidia (13.0-19.0 vs. 18.0-25.0 μm) ( Crous et al. 2012). Therefore, we described D. changpingensis as a novel species, based on morphology and sequence data.

Figures

Figure 2. Diaporthe changpingensis from Robinia pseudoacacia (BJFC CF 202212141) A, B habit of conidiomata on branch C transverse section of conidioma D longitudinal section through conidioma E, F conidiophores and conidiogenous cells G alpha and beta conidia H top (left) and bottom (right) sides of colonies on potato dextrose agar (PDA) after 7 days. Scale bars: 500 μm (B, C); 200 μm (D); 10 μm (E-G).