Pestalotiopsis taxicola Y. F. Wang & C. J. You, 2024

Wang, Yifeng, Tsui, Kin-Ming, Chen, Shimei & You, Chongjuan, 2024, Diversity, pathogenicity and two new species of pestalotioid fungi (Amphisphaeriales) associated with Chinese Yew in Guangxi, China, MycoKeys 102, pp. 201-224 : 201

Pestalotiopsis taxicola Y. F. Wang & C. J. You sp. nov.

Fig. 5

Etymology.

Named after the host species, Taxus chinensis .

Holotype.

BJFC-S1954.

Conidiogenesis.

Conidiophores reduced to conidiogenous cells, indistinct. Conidiogenous cells were discrete, ampulliform, thin-walled, hyaline, smooth. Conidia fusiform to clavate, straight or slightly curved, olivaceous to brown, 4-septate, 16.5-21 × 4-6 μm, with apical and basal appendages. Basal cell obconic, hyaline, thin-walled, smooth, 2.5-4 µm; the three median cells dolioform, versicolor, pale brown to brown with septa darker than the rest of the cells, 10.5-12 µm, the second cell from base 3-4 µm; the third cell 3.5-4 µm; the fourth cell 3.5-4 µm; apical cell 2.5-4 µm, cylindrical, hyaline; 3 tubular apical appendages, arising from the apex of the apical cell each at a different point, filiform, 9.5-15 µm; basal appendage present most of the time, single, tubular, unbranched, 2-5 µm (Fig. 5c-e ). Sexual morph not observed.

Culture characteristics.

Colonies on PDA reaching 90 mm diameter after seven days at 25 °C, with an undulate and radial edge, with dense aerial mycelium on surface, initially yellow in the centre, becoming white at the margin, with white appressed mycelia radiating outwards (Fig. 5a ). Conidiomata acervular in culture on PDA, globose, 200-700 μm in diameter, solitary or aggregated in clusters, exuding black conidial masses (Fig. 5b ).

Material examined.

China, Guangxi Province, from diseased needles of Chinese yew, May 2020, Y. F. Wang (BJFC-S1954, holotype); ex-type living culture CFCC59976, living cultures CFCC59978, CFCC59979 and CFCC59980 .

Notes.

Pestalotiopsis taxicola was phylogenetically placed in a clade encompassing P. unicolor , but as a unique lineage with high support (MP/ML = 100/100) (Fig. 2 ). Compared with P. unicolor (MFLUCC 12-0276, ex-type) and P. taxicola (CFCC59976, ex-type), there were one nucleotide difference in the ITS region and nine nucleotide differences in the tef-1α region. Morphologically, P. taxicola had smaller conidia (16.5-21 × 4-6 µm) than P. unicolor (20-24.5 × 4-6 µm). In addition, P. taxicola had only one basal appendage, whereas P. unicolor had 1-2 basal appendages ( Maharachchikumbura et al. 2012). Therefore, the four isolates were designated as a new species.

Figures

Figure 2. A phylogenetic tree of Pestalotiopsis generated from MP analysis, based on combined ITS, tub 2 and tef- 1 α sequence data. Maximum Parsimony and Maximum Likelihood bootstrap values ≥ 65 % are given at the nodes. The branches with Bayesian Inference posterior probabilities ≥ 0.90 are bold. Strains from this study are marked in blue. Ex-type strains are labelled with *.

Figure 5. Pestalotiopsis taxicola (CFCC 59976) a culture on PDA b conidiomata formed on PDA c conidiogenous cells d-f conidia. Scale bars: 500 µm (b); 10 µm (c-f).