Pleosporales » Didymellaceae

Boeremia

Boeremia Aveskamp, Gruyter & Verkley, in Aveskamp, Gruyter, Woudenberg, Verkley & Crous, Stud. (2010)

 

Facesoffungi number: FoF 07128

Index Fungorum: IF 515621

 

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).

 

Type species: Boeremia exigua (Desm.) Aveskamp, Gruyter & Verkley, in Aveskamp, Gruyter, Woudenberg, Verkley & Crous, Stud. Mycol. 65: 37 (2010)

 

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) (Fig. 43). 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 (Fig. 43). 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) (Fig. 43). 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 (Fig. 43)

Distribution: Worldwide.

Phylogenetic tree generated from a maximum parsimony analysis based on a concatenated alignment of LSU, ITS, tub2 and rpb2 sequences data of Boeremia. Forty-one strains are included in the analyses, which comprise 2379 characters including gaps. Neodidymelliopsis cannabis CBS 234.37 and N. polemonii CBS 109181 are used as the outgroup taxa. The tree topology of the maximum likelihood analysis is similar to either the maximum parsimony or the Bayesian analysis. The best scoring RAxML tree with a final optimization likelihood value of − 5796.175520 is presented. The matrix had 242 distinct alignment patterns, with 8.74% of undetermined characters or gaps. Estimated base frequencies were: A = 0.239226,  C = 0.238771, G = 0.271655, T = 0.250348; substitution rates AC = 1.659257, AG = 4.372503, AT = 2.219281, CG = 0.796064, CT = 14.559800, GT = 1.000000; gamma distribution shape parameter α = 0.020000. The maximum parsimonious dataset consisted of constant 2079, 190 parsimony-informative and 110 parsimony uninformative characters. The parsimony analysis of the data matrix resulted in the maximum of two equally most parsimonious trees with a length of 433 steps (CI = 0.783, RI = 0.793, RC = 0.621, HI = 0.217) in the first tree. Maximum parsimony (MPBS) and maximum likelihood (MLBS) bootstrap support values higher than 50%, and Bayesian posterior probabilities ≥ 0.95 (PP) are shown above or below the nodes. Hyphen (“–”) indicates a value lower than 50% for MPBS and MLBS and a posterior probability lower than 0.95 for BYY. The scale bar indicates 20 changes. Ex-type strains are in bold. New isolates are shown in bold and blue.

Species:

Boeremia exigua (Desm.) Aveskamp, Gruyter & Verkley, in Aveskamp, Gruyter, Woudenberg, Verkley & Crous, Stud. Mycol. 65: 37 (2010)

Boeremia exigua var. heteromorpha (Schulzer & Sacc.) Aveskamp, Gruyter & Verkley, in Aveskamp, Gruyter, Woudenberg, Verkley & Crous, Stud. Mycol. 65: 38 (2010)

Boeremia galiicola Jayasiri, Camporesi & K.D. Hyde, in Jayasiri, Hyde, Jones, Jeewon, Ariyawansa, Bhat, Camporesi & Kang, Mycosphere 8(8): 1089 (2017)

 

 

References:

 

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.

 

 

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