Kirschsteiniothelia pini Y. Jin, W.H. Tian & Maharachch., 2024

Kirschsteiniothelia pini Y. Jin, W.H. Tian & Maharachch. , sp. nov. FIGURE 2 View FIGURE 2

MycoBank: MB854777

Holotype: HKAS 135175 View Materials

Etymology:—The species epithet refers to the host genus where the fungus was collected.

Saprobic on decaying branches of a Pinus sp. Sexual morph: not observed. Asexual morph: hyphomycetous. Colonies on branches effuse, scattered, hairy, brown or dark brown, glistening. Conidiophores 69–124 × 3.5–7 µm (x = 94.18 × 4.9 µm, n=15) wide, macronematous, mononematous, solitary, cylindrical, straight or slightly curved, brown or dark brown, unbranched, 3–8-septate, smooth, slightly tapering towards the apex, rounded at the apex, truncate at the apex. Conidiogenous cells 15–21× 3–5 µm (x = 18.29 × 4.22 µm, n=10), integrated, terminal, monoblastic, percurrent, pale brown, cylindrical. Conidia 22–45× 5–10 µm (x = 34.75 × 7.30 µm, n=30), acrogenous, solitary, smooth, obclavate, straight or slightly curved, tapering to the apex, 3–6-euseptate, becoming brown to pale towards the apex, truncate at the base.

Culture characteristics:—Conidia germinated on PDA medium within 24 h. Colonies on PDA medium reaching 30 mm in diameter after 5 weeks at 25 ° C in dark, circular, pale to dark green on the surface, with dense, velvety aerial mycelium; on reverse, circular, dark green in the central region and becoming pale green towards margin, with growing rings, with entire margin.

Material examined:— CHINA. Sichuan Province, Neijiang City, Shuangqiao Town, 102°9'58" E, 29°48'1" N, elevation 301.35 m, on decaying branches of the pini woody plant, 01 April 2023, W. H. Tian, SQZ05_3 ( HKAS 135175, holotype), ex-type culture UESTCC 24.0131.

Notes:—In the multi-locus phylogenetic tree, our new strain UESTCC 24.0131 is phylogenetically closely related to the ex-type strains of K. aquatica ( MFLUCC 16-1685) and K. cangshanensis ( MFLUCC 16-1350). However, our isolate can be differentiated from K. aquatica and K. cangshanensis by differences in the ITS barcode, with sequence identities 93.89% (461/491, 4 gaps) and 92.08% (442/480, 4 gaps), respectively. Morphologically, our collection can be distinguished from K. aquatica and K. cangshanensis . The conidiophores of our collection (69–124 × 3.5–7 μm) are comparatively shorter and narrower than K. aquatica (114–151 × 7–8 μm) and are shorter than those of K. cangshanensis (105.5–135.5 μm). The conidia of our collection are similar to K. aquatica and K. cangshanensis . Nevertheless, the conidia of K. aquatica are thick-walled and rounded at the apex, and K. cangshanensis with a gelatinous sheath at the apex ( Bao et al. 2018). Therefore, we introduce UESTCC 24.0127 as a new species.