Microdochium jianfenglingense D. H. Li, Z. X. Zhang, J. W. Xia & X. G. Zhang 2024, sp. nov.

Microdochium jianfenglingense D. H. Li, Z. X. Zhang, J. W. Xia & X. G. Zhang sp. nov. Fig. 5 Type. China • Hainan Province: Jianfengling National Forest Park, on diseased leaves of Bambusoideae sp., 12 April 2023, D. H. Li (HMAS 352971, holotype), ex-holotype living culture SAUCC 1862-2 = CGMCC 3.27947. Etymology. The epithet jianfenglingense refers to the Jianfengling National Forest Park, where the holotype was collected. Description. Conidiophores simple, hyaline, cylindrical to clavate, sometimes reduced to conidiogenous cells. Conidiogenous cells straight or slightly curved, 15.0–25.5 × 1.9–3.0 μm, monoblastic or polyblastic, terminal, denticulate, transparent, smooth, cylindrical and septate and produced on aerial mycelia. Conidia are solitary, hyaline, often 3 - septate, spindle, oblong to ellipsoid, straight or curved, 13.0–24.0 × 2.5–4.5 μm, mean ± SD = 17.5 ± 2.5 × 3.4 ± 0.5 μm, n = 30, multi-guttulate and sometimes borne directly from the hyphae. No chlamydospores were observed. Sexual morph unknown. Culture characteristics. The colonies diameter reached 69–72 mm after 14 days of dark culture at 25 ° C on PDA, colonies exhibited concentric spreading, fluffy, marginal aerial mycelium white to cream, gradually turning tawny towards the centre; reverse white to tawny. The colonies diameter reached 64–74 mm after 14 days of dark culture at 25 ° C on OA, colonies concentrically spreading, fluffy, aerial mycelium milky white, substrate mycelium grey in the medium; reverse white. Additional material studied. China • Hainan Province: Jianfengling National Forest Park, on diseased leaves of Bambusoideae sp., 12 April 2023, D. H. Li, HSAUP 1862-5, living culture SAUCC 1862-5. Notes. Phylogenetic analyses of four combined sequences (ITS, LSU, RPB 2 and TUB 2) showed that Microdochium jianfenglingense constitutes a distinct clade, closely affiliated with M. bambusae (SAUCC 1862-1 and SAUCC 1866-1) and M. indocalami (SAUCC 1016). Microdochium jianfenglingense is distinguished from M. bambusae (SAUCC 1866-1) by 7 / 535, 3 / 828 and 59 / 912 characters and from M. indocalami (SAUCC 1016) by 24 / 539, 1 / 832 and 48 / 840 characters in ITS, LSU and RPB 2 sequences, respectively. Morphologically, the conidia of M. jianfenglingense are longer than M. bambusae and M. indocalami (13.0–24.0 × 2.5–4.5 μm vs. 13.0–17.0 × 2.5–3.5 μm vs. 13.0–15.5 × 3.5–5.5 μm). Conidiogenous cells of M. jianfenglingense are shorter than M. bambusae and M. indocalami (15.0–25.5 × 1.9–3.0 μm vs. 17.4–30.0 × 2.5–3.0 μm vs. 11.0–28.3 × 1.5–2.9 μm) (Huang et al. 2020; Zhang et al. 2023).