Nectria balansae Speg., Anales Mus. Nac. Hist. Nat.

Yang, Qin, Du, Zhuo, Liang, Ying-Mei & Tian, Cheng-Ming, 2018, Molecular phylogeny of Nectria species associated with dieback and canker diseases in China, with a new species described, Phytotaxa 356 (3), pp. 199-214 : 205-206

Nectria balansae Speg., Anales Mus. Nac. Hist. Nat. Buenos Aires 19: 36. 1885. FIGURE 3 .

Host/distribution:—Pathogen on twigs and branches of Aphananthe aspera , Gleditsia sinensis , and Hibiscus syriacus . Known from Celtis tala , Parkinsonia aculeata in Argentina, Cedrela brasiliensis in Brazil, and a Coronilla sp. in France ( Samuels & Brayford 1994, Hirooka et al. 2011, 2012, Jaklitsch & Voglmayr 2014, Lombard et al. 2015).

Asexual morph:—Not seen on natural substratum.

Sexual morph:— Mycelium invisible around ascomata or on host. Stromata erumpent through epidermis, up to 2.5 mm in height and 3.0 mm in diameter, red to sienna, KOH+ blood red, LA+ yellow, pseudoparenchymatous, cells forming textura angularis, intergrading with basal ascomatal wall. Perithecia superficial on a well-developed stroma, aggregated in groups of 2–25, red, subglobose to globose, 333–650 μm in height, 325–520 μm in diameter (n = 50), not becoming cupulate upon drying, apical region slightly darker, KOH+ dark purple, LA+ yellow, wall is warted. Ascomatal surface cells at edge of stroma forming textura globulosa or t. angularis, 5–15 μm in diameter, walls 2.5 μm thick; ascomatal warts apricot to red, 40–65 μm in height, larger in upper part of ascomata or around ostiole. Ascomatal wall at edge of stroma is 62–105 μm thick, consisting of two regions: outer region 46–67 μm thick, intergrading with stroma, cells forming textura globulosa or t. angularis, walls pigmented, approximately 2.0 μm thick; inner region 16–38 μm thick, consisting of elongate, thin-walled, hyaline cells, forming textura prismatica. Asci clavate, 8-spored, with inconspicuous ring at apex, mainly biseriate above, uniseriate below, 83–124 × 15–22 μm. Ascospores ellipsoidal, fusiform to long oblong, straight to rarely slightly curved, (19.0–)24.0–30.0(–31.5) × (7.0–)9.5–11.5(–12.5) μm (n = 50), (0–)1-septate, hyaline to slightly yellowish-brown, finely striate.

Cultures:—Colony surface is cottony with aerial mycelium whitish yellow; aerial mycelium restricted to the center; reverse whitish yellow to yellow in center and white at the margin.

Materials examined:— CHINA, Zhejiang Province, Hangzhou City , 30°18′41.00″N, 119°26′38.34″E, alt. 194 m., on twigs and branches of Hibiscus syriacus, Q. Yang & Z. Du , 21 April 2017 ( BJFC-S1388 ; living culture, CFCC 52119 ) ; ibid. 30°19′31.56″N, 119°26′29.22″E, alt. 390 m, on twigs and branches of Aphananthe aspera, Q. Yang & Z. Du , 20 April 2017 ( BJFC-S1389 ; living culture, CFCC 52120 ) ; 35°15′07.22″N, 120°07′01.77″E, alt. 21 m, on twigs and branches of Gleditsia sinensis, Q. Yang & Z. Du , 17 April 2017 ( BJFC-S1390 ; living culture, CFCC 52121 ) .

Notes:—In the current study, the isolates CFCC 52119, 52120, and 52121 were shown to be Nectria balansae based on the phylogenetic analyses and their morphological characteristics. This is the first reported record of N. balansae on Aphananthe aspera , Hibiscus syriacus , and Gleditsia sinensis in China. Teng (1934) described Nectria sinensis , which was regarded as a synonym of N. balansae by Hirooka et al. (2012). However, the holotype specimen of N. sinensis was destroyed during the Second World War II. Hirooka et al. (2012) designated a duplicate type specimen at BPI 551019 as lectotype. Nectria sinensis was re-described by Zhuang (2013) from HMAS 183561. That description of N. sinensis agrees well with Hirooka et al. (2011), except in the observation of its asci, which are wider (20–27 μm vs. 13.5–16.5 μm). Hence, molecular data is required to differentiate these two species.

Figures

FIGURE 3. Morphology of Nectria balansae from Aphananthe aspera (BJFC-S1389). A: Host branch. B–D: Perithecia on natural substrata. E–F: Median section of perithecium. G, J, K: Ascospores. H–I: Asci. Scale bars: B–E = 500 μm; F, H, I = 50 μm; G, J, K = 20 μm.