Entomosporium dichotomanthes H. D. Yang, Jayaward & K. D. Hyde, 2024

Yang, Hong De, Jayawardena, Ruvishika S., Zeng, Xiang Yu, Thiyagaraja, Vinodhini, Zhao, Qi & Hyde, Kevin D., 2024, Recommendations on approving the name “ Entomosporium ”, with a new species, E. dichotomanthes from China (Leotiomycetes, Drepanopezizaceae), MycoKeys 107, pp. 1-20 : 1-20

Entomosporium dichotomanthes H. D. Yang, Jayaward & K. D. Hyde sp. nov.

Fig. 4

Etymology.

The species epithet ‘ dichotomanthes ’ refers to the host Dichotomanthes tristaniicarpa in which the holotype was collected.

Holotype.

HKAS 131154 .

Description.

Parasitic on leaf of Dichotomanthes tristaniicarpa in terrestrial habitat. Leaf spots: appear as tiny black spots or irregular black stripes on the upper side of the mature leaf when young, without injured disease symptoms. Later the spot enlarged to circular lesions or large dead areas with black edege. The area around the black spots remains green. Sexual morph: Not determined. Asexual morph: Conidiomata dark brown to black, stromatic, acervular, epiphyllous, solitary to gregarious or confluent, subcuticular to rounded or irregular in outline, rugose, erumpent through the cuticle. Conidiomatal wall mixed with host plant tissue, of several layers loose textura angularis cell. Conidiophores hyaline to pale brown, cylindrical, branched. Conidiogenous cells 5.0–8.4 × 2.8–4.4 µm, hyaline, cylindrical, holoblastic. Conidia hyaline, 3–4 - celled, cruciform, the basal cell developed from the conidiogenous cell, and other cells attached to basal cell in both upper sides and apex. Basal cells 6.7–12.1 × 4.5–8.6 (avg. = 9.9 × 7.1, n = 30) µm, cylindrical, globose to obovate. Apical cell 5.8–13.0 × 5.1–10.7 (avg. = 9.9 × 8.0, n = 30) µm, globose to subglobose, the end with a tubular appendage. Lateral cells 3.5–7.5 × 2.5–4.1 (avg. = 5.7 × 4.1, n = 20) µm, subglobose to ellipsoidal, the end with a tubular appendage.

Material examined.

China, Yunnan Province, Kunming City, Longchuanqiao park , 25 ° 8 ' 15.65 " N, 102 ° 47 ' 13.70 " E, on living leaf of Dichotomanthes tristaniicarpa , 14 December 2021, YHD 239-5 ( HKAS 131154 ); YHD 202 .

Notes.

Entomosporium dichotomanthes is characterized by having three to four cells of conidia. Its morphology resembles D. mespili and D. mespilicola , but has different host plants association and distribution. E. dichotomanthes is easily detectable on the host substrate in the mountains around the lake of Longchuanqiao Park. However, we couldn’t find this fungus on nearby plants of the host, or on other plants in the mountains. We also failed to isolate the culture by using both single spore isolation and tissue isolation methods which indicates E. dichotomanthes strictly rely on D. tristaniicarpa .

Figures

Figure 4. Entomosporium dichotomanthes (HKAS 131154, holotype) a, b disease symptoms on the leaves, c – e conidiomata f, g conidiogenous cells and conidia, h – k conidia. Scale bars: 50 µm (e); 10 µm (f – k).