Cytospora myricicola Ning Jiang, 2024

Li, Jiangrong, Li, Jieting & Jiang, Ning, 2024, Morphology and phylogeny of Cytospora (Cytosporaceae, Diaporthales) species associated with plant cankers in Tibet, China, MycoKeys 104, pp. 51-70 : 51

Cytospora myricicola Ning Jiang sp. nov.

Fig. 2

Etymology.

" myrici " refers to the host genus Myricaria and "- cola " means inhabiting.

Holotype.

CAF800083.

Description.

Associated with branch canker disease of Myricaria paniculate . Sexual morph: Undetermined. Asexual morph: Pycnidial stromata ostiolated, semi-immersed in the host bark, scattered, discoid, with multiple locules. Conceptacle dark brown to black, circular surrounded stromata. Ectostromatic disc dark yellow, circular to ovoid, (250-)350-450(-550) μm diam., with one ostiole per disc. Ostioles dark, at the same level as the disc, (35-)55-85(-100) μm diam. Locule numerous, arranged circularly or elliptically with independent walls (245-)300-450(-550) μm diam. Peridium comprising a few layers of cells of textura angularis, with innermost layer brown, outer layer brown to dark brown. Conidiophores hyaline, branched, thin-walled, filamentous. Conidiogenous cells enteroblastic polyphialidic, 6.5-35.5 × 1.5-2.5 μm. Conidia hyaline, allantoid, smooth, aseptate, thin-walled, (4.4-)4.7-5.6(-5.8) × 1.4-1.7 μm (x̄ = 5.2 × 1.6 μm).

Culture characteristics.

Colonies on PDA flat, with flocculent aerial mycelium and entire edge, initially white, becoming dark and reaching 90 mm diameter after 10 days at 25 °C, sterile.

Materials examined.

China, Tibet Tibetan Autonomous Region, Lhasa City , Mozhugongka County, Riduo Township , Zen Village , on cankered branches of Myricaria paniculate , 28 July 2022, Jin Peng, Liu Yuanyuan, Jiang Ning and Liu Min (CAF800083, holotype); ex-type culture CFCC 59323 . China, Tibet Tibetan Autonomous Region, Lhasa City , Mozhugongka County, Riduo Township , Renqinglin Village , on cankered branches of Myricaria paniculate , 28 July 2022, Jin Peng, Liu Yuanyuan, Jiang Ning and Liu Min (XZ010B); cultures CFCC 59324 and CFCC 59325 .

Notes.

Phylogenetically, Cytospora myricicola is close to C. fraxinigena , C. junipericola , C. pubescentis , C. quercicola and C. rosae (Fig. 1 ). Of these six species, only C. myricicola , C. pubescentis and C. rosae have asexual morph descriptions; C. myricicola (4.7-5.6 × 1.4-1.7 μm) is different from C. pubescentis (5.8-7.5 × 1.3-1.6 μm) by shorter conidia and from C. rosae (3-5 × 0.5-1 μm) by larger conidia ( Senanayake et al. 2017; Shang et al. 2020). In addition, C. myricicola can be distinguished from the other five species by host and distribution ( C. myricicola from Myricaria paniculate in China vs. C. fraxinigena from Fraxinus ornus in Italy vs. C. junipericola from Juniperus communis in Italy vs. C. pubescentis from Quercus pubescens in Italy vs. C. quercicola from Quercus sp. in Italy vs. C. rosae from Rosa canina in Italy) ( Senanayake et al. 2017; Shang et al. 2020).

Figures

Figure 1. Maximum Likelihood tree generated from combined ITS, act, rpb 2, tef 1 and tub 2 sequence data. Bootstrap support values ≥ 50 % and Bayesian posterior probabilities ≥ 0.90 are demonstrated at the branches. Ex-type cultures are marked with (*).

Figure 2. Cytospora myricicola (CAF 800083, holotype) A, B canker disease symptom C conidioma D transverse section through a conidioma E longitudinal section through a conidioma F conidiophores and conidia G, H conidia. Scale bars: 2000 µm (B); 1000 µm (C, D); 500 µm (E); 10 µm (F-H).