Cytospora elaeagni Allesch., Hedwigia

Fan, Xin-Lei, Hyde, Kevin D., Yang, Qin, Liang, Ying-Mei, Ma, Rong & Tian, Cheng-Ming, 2015, Cytospora species associated with canker disease of three anti-desertification plants in northwestern China, Phytotaxa 197 (4), pp. 227-244 : 235

Cytospora elaeagni Allesch., Hedwigia 36 (Beibl.): 162 (1897) ( Fig. 5 )

Host and Distribution:—Known from Elaeagnus angustifolia in, China, German and USA.

Pathogen on twigs and branches of Elaeagnus angustifolia . Sexual state:—Unknown.

Asexual state:—Stromata immersed in bark. Conidiomata, slightly erumpent through the surface of bark, discoid, nearly flat, with small multiple locules. Conceptacle absent. Disc dark, unconspicuous, circular to ovoid, (70–) 90– 140(–150) μm (average = 110 μm, n = 20) in diameter, with one ostiole per disc. Ostiole in the center of the disc, unconspicuous, at the same level as the disc surface, (49.8–)51.8–62.8(–63.4) μm (average = 57.8 μm, n = 20) in diameter. Multi-locules arranged in circles or ellipse with common walls, (580–)630–920(–940) μm (average = 790 μm, n = 20) in diameter. Conidiophores hyaline, unbranched or branched at the bases, (14.2–)16.8–27.4(–28.1) μm (average = 22.5 μm, n = 20). Conidia hyaline, elongate-allantoid, eguttulate, aseptate, (6.1–)6.3–9.3(–9.6) × (1.7–)2– 2.9(–3) μm (average = 7.7 × 2.6 μm, n = 50).

Cultures:—Colony originally white, producing light brown pigment after 7–10 days, flat, with a thick texture at the center with thin surrounding texture, conidiomata irregular on medium surface.

Material examined:— CHINA Qinghai Province: Haidong District , Pingan County, Bazang Gou , 36°27’32.44” N, 102°09’16.90” E, 1348 m asl., on twigs and branches of Elaeagnus angustifolia , collected by X. L. Fan, 15 Aug 2012 ( BJFC-S642 ) ; living culture, CFCC 89631 ; Ningxia Province, Guyuan, Changchengliang , 36°03’01.77” N, 106°16’18.63” E, 1767 m asl., on twigs and branches of Elaeagnus angustifolia , collected by X. L. Fan, 24 Jul 2013 ( BJFC-S965 ) ; living culture, CFCC 89632 ; ibid., living culture, CFCC 89633 .

Notes: Cytospora elaeagni has been recorded from Elaeagnus angustifolia in China, Germany and North America, but these records lacked any detailed descriptions, illustrations, and molecular data ( Saccardo 1889; Chen 2002; Zhuang 2005). In the current study, the isolates CFCC 89631 and CFCC 89632 were shown to be C. elaeagni based on previous described morphological characters, host, and distribution ( Saccardo 1889, Zhuang 2005). Therefore, this species from E. angustifolia was redescribed firstly based on morphology and phylogeny.

Cytospora elaeagni has not been epitypified and therefore we treat BJFC-S965 as an authentic specimen. This has been proved as consistent results from several other authors without epitypification ( Saccardo 1889, Zhuang 2005). It makes sense to epitypify this here for further study. Thus fresh collections of Cytospora elaeagni are needed for epitypification.

Figures

FIGURE 5. Morphology of Cytospora elaeagni from Elaeagnus angustifolia (BJFC-S642). a, d: Habit of conidiomata on a twig. b, c: Longitudinal sections through conidiomata. e, f: Transverse sections through conidiomata. g: Conidiophores. h: Conidia. i: Colonies on PDA at 3 days (left) and 30 days (right). Scale bars: a=1 mm; b–f=0.5 mm; g=20 μm; h=5 μm.