Boeremia Aveskamp, Gruyter & Verkley, in Aveskamp, Gruyter, Woudenberg, Verkley & Crous, Stud. (2010)
Facesoffungi number: FoF 07128
Dothideomycetes, Pleosporomycetidae, Pleosporales, Didymellaceae
Saprobic or parasitic on the host plant in terrestrial habitat or from soil. Sexual morph: see Aveskamp et al. (2010) and Jayasiri et al. (2017). Asexual morph: Conidiomata dark brown to black, pycnidial, solitary to gregarious, subperidermal, immersed or semi-immersed, variable in shape and size, mostly globose to subglobose, unilocular, glabrous, ostiolate. Ostiole single, non-papillate or papillate, lined internally with hyaline cells when mature, centrally or laterally located. Conidiomatal wall composed of thick-walled, pale brown to hyaline cells of textura angularis or sometimes textura globosa. Conidiophores reduced to conidiogenous cells. Conidiogenous cells hyaline, enteroblastic, phialidic, determinate, doliiform to ampulliform, formed from the inner layer cells of the conidiomata. Conidia hyaline, variable in shape, mostly aseptate, sometimes 1–2-septate, straight or slightly curved, thick and smooth-walled, often guttulate (Aveskamp et al. 2010).
Figure 1 – Boeremia exigua var. pseudolilacis (redrawn from Aveskamp et al. 2010) a Pycnidia. b Section of young pycnidium. c Conidia. Scale bars: a = 100 µm, b = 20 µm, c = 5 µm.
Notes: Since Boeremia was introduced, 23 species and varieties have been accepted in the genus (Aveskamp et al. 2010; Chen et al. 2015, 2017; Jayasiri et al. 2017). Phylogenetic analyses based on LSU, ITS, rpb2 and tub2 sequence data indicated that a new collection (MFLU 15-1341) clustered with B. galiicola (MFLUCC 15-2279). Morphologically, the new collection shares a similar form of conidiomata and conidia with the asexual morph of B. galiicola, but differs in conidial septation and dimensions. However, it should be noted that in some coelomyceyes, conidial septation and dimensions on natural substrate may differ from those found in culture. Based on phylogeny, morphology, and host, this new collection is regarded as conspecific with B. galiicola, and an improved photo plate of the asexual morph is provided. Two strains (CBS 109183, CBS 119730) were named as B. exigua var. coffeae (Chen et al. 2017), but they formed two distinct branches. Since the B. exigua var. coffeae was originally introduced based on strain CBS 109183 collected from Coffea arabica in Brazil, strain CBS 119730 collected from Camernoon is treated as Boeremia sp. Varieties B. exigua var. exigua (CBS 431.74), B. exigua var. forsythia (CBS 101213, CBS 101197), B. exigua var. gilvescens (CBS 101150) and B. exigua var. viburni (CBS 100354) nested with two strains of B.exigua (CBS 118.38, CBS 119.38). Based on phylogeny, these varieties are considered as conspecific species with the generic type B. exigua. Similarly, variety B. exigua var. populi (CBS 100167) is reduced to a synonym of B. exigua var. heteromorpha on the basis of molecular data.
Li W, McKenzie E, Liu J, Bhat D, Dai D, Camporesi E, Tian Q, Maharachchikumbura S, Luo Z, Shang Q, Zhang J, Tangthirasunun N, Karunarathna S, Xu J and Hyde K– 2020. Taxonomy and phylogeny of hyaline-spored coelomycetes. Fungal Diversity, 100(1), pp.279-801.