Moelleriella sinensis Jun Z. Qiu & Y.X. Chen, 2020

Chen, Yu-Xi, Xue, Qing-Lin, Xie, Yong-Xiao, Keyhani, Nemat O., Guan, Xia-Yu, Wei, Xiu-Yan, Zhao, Juan, Yan, Zhong, Chen, Hui, Qiu, Jun-Zhi & Guan, Xiong, 2020, Moelleriella sinensis sp. nov. (Clavicipitaceae, Ascomycota) from southeast China, Phytotaxa 429 (4), pp. 289-296 : 292-295

Moelleriella sinensis Jun Z. Qiu & Y.X. Chen , sp. nov. FIGURE 1

MycoBank: MB 829897

Index Fungorum: IF556854

Etymology.— sinensis , referring to the type locality China.

Holotype.— CHINA, Fujian Province, Wuyishan City, Wu Yi Mountain, alt. 1000 m, on infected whitefly ( Hemiptera , Aleyrodidae ) nymphs; on the underside of leaves of dicotyledonous plants, 5 Oct 2017, J.Z. Qiu, HMAS247790 (ex-holotype strain, CGMCC 3.18911); Gene sequences of ex-holotype strain: MK412091 (LSU), MK393868 (TEF-1α), MK412101 (RPB1).

Anamorph.—Parasitic on whitefly nymphs ( Hemiptera , Aleyrodidae , Bemisia sp. ). Stromata usually flattened pulvinate to discoid, narrowing towards base (stud-shaped) and then widening obviously, 1.1–3.3 × 0.3–0.6 mm (x̅ = 1.9 × 0.4 mm, n = 10), whitish to pale yellow, surface minutely tomentum, base surrounded by a white to pale brown membranous hypothallus, up to 1.2 mm wide, no reaction to 3 % KOH. Conidiomata orifice scattered, ultimately hidden by the pale brown mass or extruded conidia, oval, elongate flask shaped or irregular in shape, 103.6–279.6 × 83.1–145.5 μm (x̅ = 181.7 × 108.8 μm, n = 20). Wall of conidiomata 33–65 μm wide, composed of thick-walled, pale brown to hyaline cells. Conidiophore reduced to conidiogeneous cells. Conidiogenous cells cylindrical, up to 30 μm long, 0.8–1.3 μm wide. Conidia fusoid, tapering slightly toward the ends, hyaline, yellowish-orange to pale brown in mass, 6.7–11 ×1.3–1.8 μm (x̅ = 8.8 × 1.5 μm, n = 30), L = 8.79 μm, W= 1.53 μm, Q = 5.71 (n = 30/1). Paraphyses present, filiform, 43.2–68.9 × 0.6–0.8 μm (x̅ = 57.5 × 0.7 μm, n = 30). Teleomorph not observed.

Cultural characteristics.— Conidia germinating within 24 h on PDA. Colonies on PDA at 25 °C; fast-growing, compact, yellow to pale brown, attaining ca. 1.6 cm diameter after 2 weeks. Optimal temperature 20–26 °C, with no growth below 5 °C or above 35 °C. Stromatic colonies: pale brownish, forming moderately compact stromata, with a rough surface, knobby protuberances, and curled margin. Conidial masses: yellowish orange to pale brown, abundant, appearing on the surface of stromatic colonies after ca. 2 weeks.

Additional material examined.— CHINA, Fujian Province, Wuyishan City, Wu Yi Mountain, on whitefly ( Hemiptera , Aleyrodidae , Bemisia sp. ) nymphs on the underside of leaves, 5 Oct 2017, J.Z. Qiu (paratype HMAS247791; ex-paratype culture CGMCC 3.18912).

Remarks.— Moelleriella sinensis is mainly characterized by its whitish to pale yellow pulvinate stroma, pale brown mass of extruded spores and fusiform conidia. Moreover, M. sinensis was compared morphologically with several species including Moelleriella pongdueatensis Mongkol. et al. , Moelleriella phukhiaoensis Mongkol. et al. , Moelleriella pumatensis T.T. Nguyen & N.L. Tran , Moelleriella mollii Petch from the Old World ( Chaverri et al. 2008, Mongkolsamrit et al. 2011, 2015, Li et al. 2016). However, the anamorph of M. sinensis differs from M. pongdueatensis in having somewhat smaller conidia than described for M. pongdueatensis by Li et al. (2016) 6.7–11 × 1.3–1.8 μm vs. 9–12.5 × 1.5–2.5 μm and narrower paraphyses (43.2–68.9 × 0.6–0.8 μm vs. ~110 × 1–2 μm); Another important morphological/developmental difference is the absence of hirsutella -like synanamorphs simultaneously on stromata in nature for the examined species, whereas M. pongdueatensis has hirsutella -like synanamorphs simultaneously occurring on stromata in nature. Based on our observation, the anamorph of M. sinensis differs significantly from M. phukhiaoensis and M. pumatensis in having smaller stromata (1.1–3.3 × 0.3–0.6 mm vs. ~5 × 2 mm, 1.1–3.3 × 0.3–0.6 mm vs. 2.5 × 1 mm, respectively), shorter and narrower paraphyses (~69 × 0.7 μm vs. ~90 ×1–2 μm, ~69 × 0.7 μm vs. ~180 × 1.5 μm, respectively) and smaller conidia (6.7–11 × 1.3–1.8 μm vs. 16–17 × 2.5–3.5 μm, 6.7–11 × 1.3–1.8 μm vs. 12–15 × 2–2.5 μm, respectively).

The described Chinese specimens were similar to M. ochracea (= Aschersonia andropogonis ) in having pulvinate stroma, colored spore masses and fusiform conidia. However, in the anamorph, M. sinensis produces pale brown conidial masses on the stroma, whereas the conidial mass of M. ochracea are yellow, yellowish orange to orange. In addition, the sizes of the conidiogenous cells differs between the described M. sinensis and M. ochracea ; M. sinensis produces longer and narrower conidiogenous cells (15–30 × 0.8–1.3 μm) in comparison with that of the latter (7–16 × 1–1.5 μm). In addition, the anamorph of M. sinensis is distinguished from M. mollii (= Aschersonia confluens ) as M. mollii is almost identical to M. ochracea .

Phylogenetic analyses

DNA was extracted from the two fungal isolates CGMCC 3.18911 and CGMCC 3.18912 and used for PCR amplification and sequencing of the nucleotide sequences of nuclear ribosomal large subunit rRNA gene (LSU), RNA polymerase subunit 1 (RPB1) and translation elongation factor 1-α (TEF-1α) as detailed in the Methods section. Genomic fragments corresponding to LSU (805 bp), RBP1 (647 bp), and TEF-1α (897 bp) were obtained and sequenced and the resultant sequences were used in initial BLAST analyses, revealing relatedness to Moelleriella . In order to clarify the phylogenetic position of the unknown isolates, sixty-seven selected closely related taxa were retrieved from GenBank. Balansia henningsiana was used as outgroup for the final analyses. Of the 2349-character alignment in the combined data set, 648 characters were parsimony informative. Maximum parsimony analyses of this data set yielded one parsimonious tree (tree length 1514; CI = 0.5059, RI = 0.7642, RC = 0.3866, HI = 0.4941, FIGURE 2 ). These analyses place the two anamorphic isolates, CGMCC 3.18911 and CGMCC 3.18912, in a distinct group indicating that they represent a distinct species, residing in the strongly supported Moelleriella clade. Overall, the DNA sequence analyses of LSU, RPB1 and TEF-1α support M. sinensis as a new species forming a distinct clade sister to the M. mollii / M. ochracea clade.

Figures

FIGURE 1. Moelleriella sinensis (CGMCC3.18911, holotype). A Habitat. B Stroma on the underside of leaves. C Flank of stroma. D, E Frontage of stroma. F Colonies on PDA media. G Longitudinal section of stroma. H, I Section of pycnidium. J Conidiogenous cells. K Conidia. Scale is indicated by bars (B = 1 cm; C-E = 0.2 mm; F = 0.5 cm; G = 100 μm; H,I = 20 μm; J,K = 10 μm).

FIGURE 2. Phylogenetic analyses of Moelleriella sinensis and related species using maximum likelihood and maximum parsimony analyses of the TEF-1α, LSU and RPB1. Numbers above each branch stand for bootstrap support from 1000 replicates.