Podonectria multiarmata X. L. Xu & C. L. Yang, 2025

Podonectria multiarmata X. L. Xu & C. L. Yang sp. nov.

Fig. 10 View Figure 10

Etymology.

Refers to the species having conidia bearing multiple arm-like extensions.

Diagnosis.

Similar to species of Podonectria , P. multiarmata differs notably in sporulation and conidial morphology, particularly in the extension patterns, size, and septation of the conidial arms.

Type.

CHINA • Sichuan Province, Meishan City, Hongya County. Infected scale insects ( Kuwanaspis howardi ) were found on the culms of bamboo ( Pleioblastus amarus ), 29°41.88'N, 103°14.04'E, alt. 540 m, 13 Mar. 2021, C. L. Yang, YCL 202103005 ( SICAU 25-0084 – holotype preserved in the Herbarium of Sichuan Agricultural University; living culture SICAUCC 25-0065 – ex-holotype stored in the Culture Collection in Sichuan Agricultural University) GoogleMaps .

Description.

Habitat associated with scale insects Kuwanaspis howardi on Pleioblastus amarus ( Poaceae ). Sexual morph: Not observed. Asexual morph: Hyphomycetes. Colonies surround the scale insects, effuse, white, and diffuse outward to produce thin layers of hyphae. Mycelia branched, septate, 1–3 µm wide. Conidiophores inconspicuous, mononematous, short, straight or slightly curved, mostly reduced to conidiogenous cells. Conidiogenous cells subglobose to globose, acrogenous, determinate hyaline, with obviously conidiogenous loci, 4–6 × 4–7 µm. Conidia usually with two and three arms, V-shaped, Y-shaped or T-shaped, occasionally four arms, smooth, hyaline, each arm varies in length and sharply divergent, slightly constricted at the septa, straight or curved, and tapering toward the apical cell, 1–4 septate for each arm, 20–40 (– 50) µm long, 3.5–6 wide at the base, 1.5–3 wide near the apex. All arms arise from a bigger basal cell, measuring 6–8 µm wide.

Culture characteristics.

Conidia germinate on PDA within 12 h, with the germination tube usually growing from the tip of the arm. Colonies grow slowly on PDA, reaching 2.5 cm in diameter after 20 days at 25 ° C, flat, circular, white, gradually becoming light fleshy pink, and the back of colonies yellow.

Host.

Kuwanaspis howardi ( Coccidae ).

Habitat.

Subtropical monsoon evergreen broad-leaf forests serve as the habitat for Podonectria multiarmata , which infects scale insects found on the culms of bamboo. Infections are typically observed in moist, shaded environments.

Distribution.

China, Sichuan Province, Meishan City.

Material examined.

CHINA • Sichuan Province, Meishan City , Hongya County. Infected scale insects ( Kuwanaspis howardi ) were found on the culms of Pleioblastus amarus , 29°41.88'N, 103°14.04'E, alt. 540 m, 15 Mar. 2021, C. L. Yang, YCL 202103005 ( SICAU 25-0084 , living culture SICAUCC 25-0065 ) GoogleMaps ; • ibid. YCL 202103005-1 ( SICAU 25-0085 , living culture SICAUCC 25-0066 ) GoogleMaps .

Notes.

Our collections clustered phylogenetically with species of Podonectria based on combined ITS, LSU, SSU, rpb 2, and tef 1 - α sequence data (Fig. 3 View Figure 3 ) (100 % MLBS, 1.00 BIPP). Nucleotide BLAST sequence showed distinguishing identities with those related species P. sichuanensis ( SICAU 16-0003 ), P. coccicola (pAak), P. novae-zelandiae ( SICAUCC 21-0004 ), and P. kuwanaspidis ( SICAUCC 21-0002 ) in ITS (90.38 %, 88.45 %, 89.89 %, 88.26 %), LSU (96.77 %, 98.26 %, 97.92 %, 98.62 %), SSU (99.62 %, -, 99.81 %, 100 %), tef 1 - a (95.34 %, -, 94.35 %, 95.34 %), and rpb 2 (93.20 %, -, 90.74 %, 90.39 %), respectively. Podonectria multiarmata resembles other Podonectria species in its asexual state, producing conidia with arms that are joined at a basal cell ( Xu et al. 2021 a). However, it differs in the length and divergence angle of each arm, and it also produces T-type and Y-type conidia with radiating divergent arms.