Pseudocamarosporium pini (Westend.) Phukhamsakda, Camporesi & K.D. Hyde, comb. nov.
Index Fungorum number: IF 551896; Facesoffungi number: FoF 01817, Fig. 2
Basionym: Hendersonia pini Westend., Bull. Acad. R. Sci. Belg., Cl. Sci.: tab. 9, no. 7 (1857)
≡ Camarosporium pini (Westend.) Sacc., Syll. fung. (Abellini) 3: 465 (1884)
Saprobic on dead cone of Pinus nigra J.F. Arnold. Sexual morph Undetermined. Asexual morph Conidiomata 105 – 174 μm high × 188 – 244 wide μm (x̄ = 145 × 210 μm, n = 5) diam., pycnidial, solitary, uniloculate, scattered, immersed to erumpent, subglobose, but sometimes irregular, brown to dark brown, ostiole central. Pycnidial wall 14 – 28 μm (–40 μm at apex), composed of 5 layers of brown-walled cells of textura angularis, hyaline inner layer lining bearing conidiogenous cells. Conidiophores reduced to conidiogenous cells. Conidiogenous cells 2 – 6 × 3 – 5 μm (x̄ = 4 × 4 μm, n = 20) diam., enteroblastic, phialidic, determinate, smooth-walled, hyaline. Conidia 7 – 18 × 4 – 8 μm (x̄ = 14 × 6 μm, n = 50), oval to oblong, curved at the apex, with 1 – 3 transverse septa, and 1 – 2 longitudinal septa at the second and third cells, initially hyaline, brown to dark brown at maturity, narrowly rounded at both ends, smooth-walled.
Culture characteristics: Colonies on PDA 60 mm diam. after 4 weeks at 16 °C, cream to white at the margins, palebrown to yellowish at the center; reverse yellowish to cream and orangish-white at the center, medium dense, circular, umbonate, fairly fluffy, without diffusible pigments.
Material examination: ITALY, Forlì-Cesena Province, Monte Mirabello – Predappio, on dead and terrestrial cone of Pinus nigra (Pinaceae), 13 Octorber 2014, E. Camporesi (MFLU 15–3290, HKAS 91937, reference specimen designed here), ex-type living culture, MFLUCC 14–1091, KUMCC 15–0550.
Note: Several Camarosporium species has been reported from Pinus spp., such as C. propinquum (Sacc.) Sacc., C. brabeji Marincowitz et al., and C. pini (Westend.) Sacc. (Grove 1937; Botella et al. 2010; Botella and Diez 2011). Wijayawardene et al. (2014a) treated C. propinquum under Pseudocamarosporium typified by P. propinquum. The strain clustered in Didymosphaeriaceae, separate from the type of Camarosporium, C. quaternatum, which clustered in Pleosporinae. Crous et al. (2015a) synonymized Camarosporium brabeji Marincowitz et al. under Pseudocamarosporium brabeji as the molecular data placed them in Didymosphaeriaceae. Camarosporium pini was originally described by Westendorp (1857) as Hendersonia pini, and the species is recorded from Pinus silvestris (Grove 1937). When comparing the morphology of our species with C. pini, they are similar in the host and morphology. The conidiomata are similar in size, with thick walls up to 40 μm wide. The dimension of conidia overlap and are oblong, rounded at both ends, with one or two longitudinal septa in the middle cells. Based on phylogenetic analysis (Fig. 1) our strain clusters within Pseudocamarosporium in Didymosphaeriaceae with relative high support (92 % MP/88 % ML /0.99 PP). We therefore synonymize Camarosporium pini under Pseudocamarosporium pini based on morphology and phylogeny, and designate our collection as a reference specimen (sensu Ariyawansa et al. 2014c), which we illustrate here.
Fig. 1 Phylogram generated from maximum parsimony analysis based on combined LSU, ITS and SSU sequenced data from species of Didymosphaeriaceae.Maximum parsimony/likelihood bootstrap support values greater than 50%and Bayesian posterior probabilities greater than 0.50 are shown in above and below. The ex-type strains are in bold and the new isolates is in blue. The tree is rooted with Pyrenochaeta protearum.
Fig. 2 Pseudocamarosporium pini (MFLU 15–3290, reference specimen) a, b Appearance of conidiomata on Pinus nigra cone c Vertical section of conidioma d Peridium e Ostiole f – i Developing stages of conidia j – o Conidia p – q Culture characters on PDA. Scale bars: c = 100 μm, d – e = 20 μm, f – o = 5 μm, p – q = 30 mm.