Neocatenulostroma endophyticum X. Yu. Zhang, Q. Y. Zhang & B. Fan, 2025

Neocatenulostroma endophyticum X. Yu. Zhang, Q. Y. Zhang & B. Fan sp. nov.

Fig. 13 View Figure 13

Type.

CHINA • Jiangsu Province, Nanjing, Nanjing Forestry University, Baima Campus , fungal endophyte from Pinus densiflora , May 2023, Ben Fan and Xiuyu Zhang, NF 685 ( holotype HMAS 352961 View Materials , culture ex-type CGMCC 3.28957 View Materials ) .

Etymology.

Derived from the Latin word “ endophyticum ,” indicating its ecological niche as an endophyte.

Description.

Mycelium composed of hyaline to pale brown, multi-septate, branched, smooth- to verruculose-walled hyphae, 2.5–3.9 μm. Asexual morph blastic-acropetal; conidiogenous cells developing from swollen hyphal segments, pale brown to brown, thick-walled, verruculose, straight to slightly curved, occasionally in short series Conidia produced successively at the apex of conidiogenous cells, forming acropetal chains; conidia hyaline to pale brown, verruculose, aseptate, ellipsoidal, relatively thick-walled, (5.2 –) 6.0–10.4 (– 13.5) × (2.6 –) 3.5–4.5 (– 4.9) μm (Fig. 13 D – H View Figure 13 ). Conidia frequently germinate laterally or apically by means of short, thin-walled germ tubes, which may elongate into hyaline hyphae or give rise to new conidial chains (Fig. 13 H View Figure 13 ). Although the conidia are relatively thick-walled and pigmented, they are not chlamydospores, as they are actively produced in conidial chains. Sexual state unknown.

Culture characteristics.

Colonies are black to dark olive in colour on MEA and OA, growing very slowly with a slightly fuzzy texture, dense in the centre and relatively loose at the edges. On SNA, aerial hyphae appear white and cottony. The optimal temperature for growth is 20–25 ° C, reaching 3–6 mm diam in 10 d. No growth at 5 ° C and 35 ° C.

Additional material examined.

CHINA • Jiangsu Province, Nanjing, Nanjing Forestry University, Baima Campus , fungal endophytes from Pinus densiflora , May 2023, Ben Fan and Xiuyu Zhang, NF 690 .

Notes.

Two endophytic fungal isolates obtained from resistant Pinus densiflora formed a distinct lineage within the genus Neocatenulostroma , showing close phylogenetic affinity to N. microsporum (Joanne E. Taylor & Crous) Quaedvl. & Crous and N. abietis (Butin & Pehl) Quaedvl. & Crous. Morphologically , Neocatenulostroma species belong to a group of black yeast-like melanized Capnodialean microfungi ( Markovskaja et al. 2016). However, unlike the present endophytic isolates, both N. microsporum and N. abietis are plant pathogens, reported from South Africa and Europe, respectively. The new taxon, N. endophyticum , differs from N. microsporum by 6.19 % (28 / 452 bp) in the ITS region, and can be further distinguished by producing slightly shorter and more variably shaped conidia (5.2–13.5 × 2.6–4.9 μm), although the size ranges partly overlap with those of its closest relatives, which are 13–15 × 5.5–6 μm in N. microsporum ( Quaedvlieg et al., 2014) and 8–24 × 5–7 μm in N. abietis ( Butin et al. 1996) .