Coniella castanea T.C. Mu, S. Wang, J.W. Xia & X.G. Zhang, 2022

Wang, Shi, Mu, Tai-Chang, Liu, Rong-Yu, Liu, Shu-Bin, Zhang, Zhao-Xue, Xia, Ji-Wen, Li, Zhuang & Zhang, Xiu-Guo, 2022, Coniella castanea sp. nov. on Castanea mollissima from Shandong Province, China, Phytotaxa 559 (1), pp. 25-34 : 30

Coniella castanea T.C. Mu, S. Wang, J.W. Xia & X.G. Zhang , sp. nov. ( Fig. 2 )

MycoBank No. 842376

Etymology. Name refers to the genus of the host plant Castanea mollissima .

Holotype. China, Shandong Province: Tai’an City , on diseased leaves of Castanea mollissima Blume , 3 Oct. 2020, T.C. Mu, HSAUP200313, ex-type living culture SAUCC200313.

Colonies on PDA, medium dense, irregular, slightly raised, wavy margin, like blooming peony, white at the margin, umber in the centre, reverse white at the margin, light brown in the centre. PDA attaining 69.5–72.7 mm in diameter after 7 days (in the darkness, 25 °C), growth rate 9.9–10.3 mm /day. Leaf spots irregular, pale yellow or yellowish-brown. Asexual morph developed on PDA: Hyphomycetous. Conidiomata solitary or aggregated, superficial, subglobose, initially appearing hyaline, becoming dark yellowish-gray with age. Conidiophores smooth, septate, branched. Conidiogenous cells subcylindrical or subglobose, 3.71–7.21 × 2.14–4.25 μm, mean ± SD = 5.1 ± 0.8 × 3.1 ± 0.4 μm. Conidia pale yellowish brown, smooth, straight or sinuous, apex acute to nearly rounded, 14.20– 22.92 × 2.51–4.11 μm, mean ± SD = 17.8 ± 1.3 × 2.8 ± 0.2 μm (l: w = 6.3). Sexual morph not observed.

Additional specimen examined. China, Shandong Province: Tai’an City , on diseased leaves of Castanea mollissima , 3 Oct 2020, Z.X. Zhang, paratype HSAUP200314, ex-paratype living culture SAUCC200314 .

Known distribution. Tai’an City, Shandong Province, China (this study).

Notes. Combined ITS, LSU, RPB2 and TEF1-α gene analysis of this study showed that our isolates (SAUCC200313, SAUCC200314) formed an distinct clade with a high support value (99%/0.99) ( Fig. 1 ). Coniella castanea differs from C. quercicola by 31 nucleotides (5/ 562 in ITS, 2/ 1172 in LSU, 15/ 768 in RPB2 and 9/ 333 in TEF1-α). Morphologically, our collections differ from C. quercicola in having large conidia (14.20–22.92 × 2.51–4.11 vs. 13.00–19.00 × 2.00–3.50 μm) (l: w, 6.3 vs. 5.3), smaller conidiogenous cells (3.71–7.21 × 2.14–4.25 vs. 8.00–16.00 × 1.00–2.50 μm) and color of conidiomata (dark yellowish-gray vs. olivaceous to black) ( Alvarez et al. 2016). Based on phylogeny, morphology and nucleotide differences, we introduce our isolates as a novel species, Coniella castanea .

Figures

FIGURE 1. Phylogram of Coniella based on combined ITS, LSU, RPB2 and TEF1-α genes. The ML and BI bootstrap support values above 70 % and 0.90 BYPP are shown at the first and second position above nodes. Strains from the current study are in red.Tree is rooted with [out group]. Some branches were shortened to fit them to the page – these are indicated by two diagonal lines with the number of times a branch was shortened indicated next to the lines.

FIGURE 2. Coniella castanea (SAUCC 200313). a Leaves of host plant. b Surface view of colony after 7 days on PDA. c Reverse view of colony after 7 days on PDA. d Conidiomata sporulating on PDA. e–k Conidiogenous cells with developing Conidia. l Conidia. Scale bars: e–l= 10 μm.