Meliola liboense Y. Z. Feng & X. Y. Zeng sp. nov.

Fig. 2

Etymology.

in reference to the location (Libo County) where the specimen was collected.

Description.

Parasitic on the surface of living leaves. Colonies 2–7 mm in diameter, hypophyllous, sometimes epiphyllous, black, dense to subdense. Hyphae superficial, straight to substraight, branched, septate, darker at septa, each cell 21–29 µm (x ̄ = 25 µm, n = 10) long, with dark brown setae. Hyphal setae 132–227 µm long, scattered, denser around ascomata, straight, 2 - dentate, acute. Appressoria 13.2–16.7 × 8.1–12 µm (x ̄ = 15.2 × 9.7 µm, n = 20), 2 - celled, brown, clavate, straight to curved, formed near septa, alternate to unilateral, antrorse. Sexual morph: Ascomata up to 120.8 µm in diameter, subdense, scattered, dark brown, globose to subglobose, outer wall rough, with a central ostiole and basal setae. Asci unitunicate, 2–3 - spored, ovoid at young state, asci wall attenuated or broken when mature, without a fixed shape. Ascospores 39.4–47.6 × 12.6–17.9 µm (x ̄ = 42.7 × 16.1 µm, n = 22), hyaline when young, becoming dark brown when mature, 4 - septate, constricted at the septa, rounded at both ends, smooth-walled. Asexual morph not observed.

Material examined.

China • Guizhou Province, Libo County, 25°18'32"N, 107°56'10"E; on living leaves of Lindera sp.; 13 Jul. 2022; Yu–Wei Liu leg.; IFRD 99008 (holotype) • ibid.; IFRD 900-10 • ibid.; 8 Apr. 2022; IFRD 900-9.

Notes.

This collection is typical of Meliola in having hyphal setae and represents the first Meliola species with DNA sequence data from Lindera. There are 6 % (541 / 576 nucleotides, 2 gaps) differences in the LSU region between M. liboense and M. variaseta and 5 % (699 / 733 nucleotides, 6 gaps) differences in the LSU region between M. liboense and M. vernalis. However, the M. vernalis has larger ascomata (up to 275 μm) and longer hyphal setae (214.5–310 vs. 132–227 µm) than M. liboense (Pinho et al. 2012 b). Although the original description of M. linderae, previously reported from the same host, is unavailable for detailed comparison, the present specimen differs clearly from known taxa based on distinct morphological traits and supported by phylogenetic analysis. Therefore, it is described herein as a new species, M. liboense.