Phylogeny and taxonomy of two new Plectosphaerella (Plectosphaerellaceae, Glomerellales) species from China Author Zhang, Zhi-Yuan Author Chen, Wan-Hao Author Zou, Xiao Author Han, Yan-Feng Author Huang, Jian-Zhong Author Liang, Zong-Qi Author Deshmukh, Sunil K. text MycoKeys 2019 57 47 60 http://dx.doi.org/10.3897/mycokeys.57.36628 journal article http://dx.doi.org/10.3897/mycokeys.57.36628 1314-4049-57-47 Plectosphaerella nauculaspora Zhi.Y. Zhang, Y.F. Han & Z.Q. Liang sp. nov. Figure 3 Etymology. From "naucula" , referring to the navicular conidia. Description. Sexual morph not observed. Asexual morph on CA. Mycelium hyaline, smooth, septate, branched and thin-walled, 1-1.2 μm ( x̄ =1.5 μm ) wide. Conidiophores solitary, unbranched or rarely branched, hyaline, smooth, thin-walled, hyphal coils not observed. Conidiogenous cells growing from short branch or directly from mycelia, phialides, discrete, polymorphic, cylindrical, sub-cylindrical or ampulliform; terminal or lateral, hyaline, smooth, gradually tapering to the apex, straight at the apex, sometimes bent or helicoid, 3-37 x 0.5-2 μm ( x̄ = 11 x 1 μm , n = 10), collarette minute, cylindrical, 0.5-1 μm deep. Conidia aggregating in slimy heads, 1- or 2-celled, mostly navicular, rarely fusiform or cylindrical, sometimes swollen at both ends, hyaline, smooth, thin-walled, 4-7 x 1-2 μm ( x̄ = 5 x 1.5 μm , n = 10) (1-septate), 3-5 x 1-1.5 μm ( x̄ = 4 x 1.5 μm , n = 6) (non-septate). Chlamydospores not observed. Figure 3. Plectosphaerella nauculaspora (HMAS 248154, holotype). A-B The front and reverse of colony on CA after 14 d at 25 °C C-D Conidia E-P Phialides. Scale bars: 10 μm ( C-P ). Culture characteristics. Colonies on PDA reaching 75-76 mm diam. in 14 d at 25 °C, milk white, flat, sub-rounded, margin regular, reverse milk white. Colonies on CA reaching 63-65 mm diam. in 14 d at 25 °C, milk white, aerial hyphae sparse, flat, margin weakly undulate to faintly fimbriate, reverse milk white. Typification. CHINA, Guizhou, Guiyang, Qianlingshan Park, 26°60'N , 106°69'E, 1220 m a.s.l., on soil, 10 Sep. 2016, collected and isolated by Zhi-Yuan Zhang, HMAS 248154 (holotype), ex-type CGMCC 3.19656 (= GZUIFR-QL8.12.1); ex-isotypes CGMCC 3.19657 (= GZUIFR-QL8.12.2). Notes. Phylogenetically, our two isolates CGMCC 3.19656 and CGMCC 3.19657 cluster together very well and form a single clade separated from the other species of Plectosphaerella ( Figure 1 ). Morphologically, Plectosphaerella nauculaspora is the only species that produces navicular conidia in this genus. Therefore, based on both morphological and phylogenetic evidence, P. nauculaspora is proposed as a novel species.