Diaporthe linzhiensis Ning Jiang, 2025

Diaporthe linzhiensis Ning Jiang sp. nov.

Fig. 7 View Figure 7

Etymology.

Named after the collection site of the type specimen, Linzhi City.

Description.

Associated with branch canker disease of Alnus nepalensis . Teleomorph: Undetermined. Anamorph: Conidiomata pycnidial, immersed in bark, scattered, erumpent through the bark surface, conical, with a solitary locule, 300–500 μm diam., 250–400 μm high. Conidiophores reduced to conidiogenous cells. Conidiogenous cells cylindrical, attenuate towards the apex, hyaline, phialidic, straight or slightly curved, 5.5–16 × 1.5–3 μm. Alpha conidia not observed. Beta conidia aseptate, hyaline, smooth, guttulate, filiform, tapering towards both ends, straight or slightly curved, (23.5 –) 24.5–29 (– 30) × 1.5–2 μm (x ̄ = 26.6 × 1.8 μm, n = 50), L / W = 12.4–19.4. Gamma conidia not observed.

Culture characteristics.

Colonies on PDA at 25 ° C are spreading, flocculent, forming abundant aerial mycelium and concentric zones with an undulate margin, initially white, turning pale luteous, and reaching a diameter of 90 mm after 10 d, sterile. Colonies on MEA at 25 ° C are flat, spreading, with a smooth entire margin, white, reaching a diameter of 60 mm after 20 d, sterile. Colonies on SNA at 25 ° C are flat, spreading, forming concentric zones with undulate margins, white, reaching 80 mm in diameter after 20 d, sterile.

Materials examined.

China • Xizang Autonomous Region (Tibet), Linzhi City, Bomi County, Tongmai Town , 30°5'53"N, 95°3'49"E, 2055 m, from branches of Alnus nepalensis , 9 Jul. 2024, Ning Jiang, Jieting Li & Haoyin Zhang (holotype CAF 800101 About CAF , ex-paratype cultures CFCC 71057 and N 266 C ) GoogleMaps .

Notes.

Diaporthe linzhiensis is phylogenetically closely related to D. alnicola , D. heterophyllae , and D. virgiliae (Fig. 2 View Figure 2 ). Both D. linzhiensis and D. alnicola infect Alnus nepalensis in China, while D. heterophyllae is found on Acacia heterophylla in France, and D. virgiliae inhabits Virgilia oroboides in South Africa ( Machingambi et al. 2015; Marín-Felix et al. 2019). Morphologically, D. linzhiensis shares a similar conidiogenous cell size with D. alnicola and D. heterophyllae , which is wider than that of D. virgiliae (5.5–16 × 1.5–3 μm in D. linzhiensis vs. 9.5–33 × 2–3 μm in D. alnicola vs. 6–9 × 1–2 μm in D. heterophyllae vs. 12.3–21.3 × 0.7–1.5 μm in D. virgiliae ). Additionally, D. linzhiensis has longer beta conidia compared to the other species (24.5–29 × 1.5–2 μm in D. linzhiensis vs. 14.5–22 × 1.5–2.5 μm in D. alnicola vs. 17–24 × 1–2 μm in D. heterophyllae vs. 17.1–25.4 × 1–1.8 μm in D. virgiliae ) ( Machingambi et al. 2015; Marín-Felix et al. 2019). At the nucleotide level, D. linzhiensis also differs from D. alnicola (ITS, 23 / 547; cal, 2 / 382; his 3, 6 / 469; tef 1, 4 / 349; tub 2, 6 / 778), D. heterophyllae (ITS, 28 / 560; cal, 11 / 420; his 3, 6 / 447; tef 1, 12 / 326; tub 2, 3 / 406), and D. virgiliae (ITS, 16 / 434; tub 2, 7 / 743).