Pestalotiopsis kendrickii Li-Hua Zhu, Hui Li & D. W. Li, 2025

Li, Hui, Bai, Yu-Qing, Xie, Jun-Ya, Li, De-Wei & Zhu, Li-Hua, 2025, Two new species of Pestalotiopsis (Amphisphaeriales, Pestalotiopsidaceae) causing needle blight of Pinus massoniana in China, MycoKeys 125, pp. 95-114 : 95-114

Pestalotiopsis kendrickii Li-Hua Zhu, Hui Li & D. W. Li sp. nov.

Fig. 5

Etymology.

The epithet is named after Dr. Bryce Kendrick to commemorate his contribution to mycology.

Culture characteristics.

On PDA medium, the front of the colony is white, with dense aerial hyphae, and the colony slightly bulges in an irregular circle within 1.5 cm from the center, with wavy edges. The center of the back is light yellow, and the color gradually becomes lighter around.

Description.

Sporadic black and gregarious conidiomata produced on PDA after 8 days under light at 25 ° C, globose, semi-immersed, black, up to 1.5 mm diam (Fig. 5 B ); Conidiophores indistinct and reduced to conidiogenous cells. Conidiogenous cells (5.3 –) 7.6–11.3 (- 13.6) × (2.3 –) 2.8–5.7 (- 6.2) µm (10.3 ± 2.3 × 4.6 ± 0.5 µm, n = 30), hyaline, ampulliform or pear shape, smooth-walled, and sometimes slightly wider at the base (Fig. 5 C ). Conidia phragmospores, (18.7 –) 19.8–22.3 (– 23.4) × (6.5 –) 7.0–7.8 (– 8.3) µm (21.1 ± 1.1 × 7.3 ± 0.5 µm, n = 30), fusoid, ellipsoid, straight to slightly curved, 4 - septate (Fig. 5 D ); basal cell obconic, hyaline, thin-walled, 3.7–5.5 μm long; three median cells doliiform, wall rugose, light brown, concolorous, septa darker than the rest of the cell (second cell from the base 3.8–5.3 μm long; third cell 3.3–4.6 μm long; fourth cell 3.8–5.3 μm long); apical cell hyaline, smooth-walled, conic or trapezoid, tapering toward the apex, 2.7–3.8 μm long, with 3–4 tubular apical appendages (mostly 3), arising from the apical crest, unbranched, filiform, inserted at the top or side of the apical cell, 10.1–18.7 μm long; basal appendage single, tubular, unbranched, centric, 2.9–6.1 μm long.

Holotype.

China • Anhui province, Quanjiao city, Washan forest farm , 32°05'06"N, 118°16'22"E (DMS), isolated from needles of Pinus massoniana , 26 April 2023, Hui Li, holotype CFCC 70475 . Holotype is a living specimen being maintained via lyophilization at the China Forestry Culture Collection Center ( CFCC), Chinese Academy of Forestry, Beijing, China, and ex-type AH 1-1 is stored at the Forest Pathology Laboratory, Nanjing Forestry University.

Habitat and host.

On needles of Pinus massoniana with needle blight.

Known distribution.

Quanjiao, Anhui Province, China.

Additional specimens examined.

China Anhui province, Quanjiao city, Washan forest farm , 32°05'06"N, 118°16'22"E (DMS), isolated from needles of Pinus massoniana , 26 April 2023, Hui Li, cultures: CFCC 70487 (= AH 1-2), CFCC 70495 (= AH 1-3), CFCC 70494 (= AH 1-4), and CFCC 70483 (= AH 1-5) .

Notes.

Pestalotiopsis foliicola , P. pinicola , and P. suae have 2–3 apical appendages, whereas P. rosea has 1–3 tubular apical appendages, some of which are branched. The number of apical appendages in P. kendrickii is 3 or 4, and the appendages are unbranched, while P. jiangsuensis has 1–4 apical appendages.

Pathogenicity test.

Five days after inoculation, needles inoculated with strains AH 1-1, AH 1-2, AH 1-3, AH 1-4, and AH 1-5 exhibited obvious gray spots (Fig. 6 ), while those inoculated with strains DB 1-1, DB 1-2, DB 1-3, DB 1-4, and DB 1-5 showed milder yellow – brown spots (Fig. 7 ). Ten days after inoculation, the lesions expanded into necrotic bands. The necrotic symptoms on needles inoculated with strains AH 1-1, AH 1-2, AH 1-3, AH 1-4, and AH 1-5 were pronounced, and the lesions had almost spread throughout the needles, forming necrotic bands with an incidence rate of 100 %. The spots on needles inoculated with strains DB 1-1, DB 1-2, DB 1-3, DB 1-4, and DB 1-5 turned reddish brown and developed into necrotic bands, also with an incidence rate of 100 %. No symptoms developed on the control needles. Pestalotiopsis liuzhouensis and P. kendrickii were successfully re-isolated from 100 % of the inoculated plants, as identified by morphological characteristics and phylogenetic analysis of ITS, thereby fulfilling Koch’s postulates.

Figures

Figure 5. Pestalotiopsis kendrickii (AH 1-1). A. Colony on PDA after 5 days at 25 ° C in darkness; B. Conidiomata and conidial masses; C. Conidiophores, conidiogenous cells, and conidia; D. Conidia. Scale bars: 500 μm (B); 20 μm (C, D).

Figure 6. Pathogenicity of representative isolates of Pestalotiopsis kendrickii (AH 1-1, AH 1-2, and AH 1-3) on Pinus massoniana. A. No symptoms were observed on control pine needles treated with sterile water after 5 days; B – D. Symptoms on pine needles inoculated with conidial suspensions of AH 1-1, AH 1-2, and AH 1-3 after 5 days, respectively; E. No symptoms were observed on control pine needles treated with sterile water after 10 days; F – H. Symptoms on pine needles inoculated with conidial suspensions of AH 1-1, AH 1-2, and AH 1-3 after 10 days.

Figure 7. Pathogenicity of representative isolates of Pestalotiopsis liuzhouensis (DB 1-1, DB 1-2, and DB 1-3) on Pinus massoniana. A. No symptoms were observed on control pine needles treated with sterile water after 5 days; B – D. Symptoms on pine needles inoculated with conidial suspensions of DB 1-1, DB 1-2, and DB 1-3 after 5 days, respectively; E. No symptoms were observed on control pine needles treated with sterile water after 10 days; F – H. Symptoms on pine needles inoculated with conidial suspensions of DB 1-1, DB 1-2, and DB 1-3 after 10 days.