Boeremia

Aveskamp et al., Stud. Mycol. 65: 36. 2010.

Classification: Dothideomycetes, Pleosporomycetidae, Pleosporales, Didymellaceae.
Type species: Boeremia exigua (Desm.) Aveskamp et al. Representative strain: CBS 431.74.
DNA barcodes (genus): LSU, ITS.
DNA barcodes (species): act, cal, rpb2, tef1, tub2.

Ascomata pseudothecial, subglobose. Asci cylindrical or subclavate, 8-spored, biseriate. Ascospores ellipsoidal, 1-septate. Conidiomata pycnidial, variable in shape and size, mostly globose to subglobose, superficial or immersed into agar, solitary or confluent; ostiole non-papillate or papillate, lined internally with hyaline cells when mature; conidiomatal wall pseudoparenchymatous, multi-layered, outer wall brown pigmented. Conidiophores reduced to conidiogenous cells. Conidiogenous cells phialidic, hyaline, smooth, ampulliform to doliiform. Conidia variable in shape, hyaline, smooth- and thin-walled, mainly aseptate, but 1(–2)-septate larger conidia may be found (adapted from Aveskamp et al. 2010).

Culture characteristics:

Colonies on OA white to dull green, grey olivaceous to olivaceous or smoke-grey, velvety, floccose to woolly, margin often regular, sometimes lobate and irregular scalloped.

Optimal media and cultivation conditions: OA or PNA at 25 °C under near-ultraviolet light (12 h light, 12 h dark) to promote sporulation.

Distribution:

Worldwide.

Hosts:

Seed-borne pathogens of Phaseolus vulgaris (Fabaceae) and noxious pathogens of Coffea arabica (Rubiaceae). Species on more than 200 host genera including Amaryllidaceae, Apocynaceae, Araliaceae, Asteraceae, Caprifoliaceae, Chenopodiaceae, Crassulaceae, Fabaceae, Lamiaceae, Linaceae, Oleaceae, Salicaceae, Solanaceae, Ulmaceae, Umbelliferae.

Disease symptoms:

Leaf spots, stem lesions, black node, bulb rot, root rot, shoot dieback.

Notes:

The genus Boeremia was established by Aveskamp et al. (2010) to accommodate phoma-like species that are morphologically similar and phylogenetically closely related to Ph. exigua. Taxa in this genus are characterised by ostioles with a hyaline inner layer of cells, with species producing aseptate and septate conidia (Aveskamp et al. 2010). Only Bo. lycopersici has thus far been recorded to have a sexual morph. Recently, Chen et al. (2015a) and Berner et al. (2015) verified the phylogenetic relationship of taxa in Boeremia performing two different combined multilocus analyses, the first one based on LSU, ITS, tub2 and rpb2 sequences, and the second on ITS, act, cal, tef1 and tub2 sequences.

References:

Boerema et al. 2004 (morphology and pathogenicity); Aveskamp et al. 2010, Chen et al. 2015 (morphology and phylogeny); Berner et al. 2015 (morphology, pathogenicity and phylogeny).
Aveskamp MM, de Gruyter J, Woudenberg JHC, et al. (2010). Highlights of the Didymellaceae: A polyphasic approach to characterise Phoma and related pleosporalean genera. Studies in Mycology 65: 1–60.
Berner D, Cavin C, Woudenberg JHC, et al. (2015). Assessment of Boeremia exigua var. rhapontica, as a biological control agent of Russian knapweed (Rhaponticum repens). Biological Control 81: 65–75.
Boerema GH, de Gruyter J, Noordeloos ME, et al. (2004). Phoma identification manual. Differentiation of specific and infra-specific taxa in culture. CABI publishing, Wallingford, UK.
Chen Q, Jiang JR, Zhang GZ, et al. (2015a). Resolving the Phoma enigma. Studies in Mycology 82: 137–217.

Table 2. DNA barcodes of accepted Boeremia spp.

Species	Isolates¹	GenBank accession numbers²						References
		ITS	*act*	*cal*	*rpb2*	*tef1*	*tub2*
Bo. crinicola	CBS 109.79	GU237737	KY484558	KY484571	KT389563	-	GU237489	Aveskamp et al. (2010), Chen et al. (2015), Berner et al. (2015)
Bo. diversispora	CBS 102.80	GU237725	EU880861	KY484575	KT389565	KY484676	GU237492	Aveskamp et al. (2009b, 2010), Chen et al. (2015), Berner et al. (2015)
Bo. exigua var. coffeae	CBS 109183	GU237748	KY484560	KY484576	KT389566	KY484678	GU237505	Aveskamp et al. (2010), Chen et al. (2015), Berner et al. (2015)
Bo. exigua var. exigua	CBS 431.74	FJ427001	EU880854	KY484584	KT389569	KY484687	FJ427112	Aveskamp et al. (2009a,b), Chen et al. (2015), Berner et al. (2015)
Bo. exigua var. forsythiae	CBS 101213	GU237723	EU880868	KY484589	KT389571	KY484692	GU237494	Aveskamp et al. (2009b, 2010), Chen et al. (2015), Berner et al. (2015)
Bo. exigua var. gilvescens	CBS 101150	GU237715	KY484562	KY484591	KT389568	KY484694	GU237495	Aveskamp et al. (2010), Chen et al. (2015), Berner et al. (2015)
Bo. exigua var. heteromorpha	CBS 443.94^NT	GU237866	EU880869	KY484598	KT389573	KY484700	GU237497	Aveskamp et al. (2009b, 2010), Chen et al. (2015), Berner et al. (2015)
Bo. exigua var. linicola	CBS 116.76	GU237754	EU880880	KY484604	KT389574	KY484705	GU237500	Aveskamp et al. (2009b, 2010), Chen et al. (2015). Berner et al. (2015)
Bo. exigua var. populi	CBS 100167^T	GU237707	EU880885	KY484605	-	KY484706	GU237501	Aveskamp et al. (2009b, 2010), Berner et al. (2015)
Bo. exigua var. pseudolilacis	CBS 101207^T	GU237721	EU880874	KY484609	-	KY484710	GU237503	Aveskamp et al. (2009b, 2010), Berner et al. (2015)
Bo. exigua var. rhapontica	CBS 113651^T	KY484662	KY484566	KY484612	-	KY484713	KY484760	Berner et al. (2015)
Bo. exigua var. viburni	CBS 100354	GU237711	EU880889	KY484613	KT389577	-	GU237506	Aveskamp et al. (2009b, 2010), Chen et al. (2015), Berner et al. (2015)
Bo. foveata	CBS 109176	GU237742	EU880892	KY484614	KT389578	KY484714	GU237508	Aveskamp et al. (2009b, 2010), Chen et al. (2015), Berner et al. (2015)
Bo. hedericola	CBS 367.91	GU237842	KY484568	KY484618	KT389579	KY484718	GU237511	Aveskamp et al. (2010), Chen et al. (2015a), Berner et al. (2015)
Bo. lilacis	CBS 569.79	GU237892	EU880875	KY484619	-	KY484721	GU237498	Aveskamp et al. (2009b, 2010), Berner et al. (2015)
Bo. lycopersici	CBS 378.67	GU237848	EU880898	KY484623	KT389580	KY484726	GU237512	Aveskamp et al. (2009b, 2010), Chen et al. (2015), Berner et al. (2015)
Bo. noackiana	CBS 100353	GU237710	EU880881	KY484624	-	KY484727	GU237514	Aveskamp et al. (2009b, 2010), Berner et al. (2015)
Bo. sambuci-nigrae	CBS 629.68^T	GU237897	KY484570	KY484630	-	KY484734	GU237517	Aveskamp et al. (2010), Berner et al. (2015)
Bo. strasseri	CBS 126.93	GU237773	EU880904	KY484631	KT389584	KY484735	GU237518	Aveskamp et al. (2009b, 2010), Chen et al. (2015), Berner et al. (2015)
Bo. telephii	CBS 109175	GU237741	EU880906	KY484633	KT389585	KY484737	GU237520	Aveskamp et al. (2009b, 2010), Chen et al. (2015), Berner et al. (2015)
Bo. trachelospermi	CGMCC 3.18222^T	KY064028	-	-	KY064033	-	KY064051	Marin-Felix et al. (2017)

¹CBS: Westerdijk Fungal Biodiversity Institute, Utrecht, the Netherlands; CGMCC: Chinese General Microbiological Culture Collection Center, Beijing, China. ^Tand^NT indicate ex-type and ex-neotype strains, respectively.

²ITS: internal transcribed spacers and intervening 5.8S nrDNA; act: partial actin gene; cal: partial calmodulin gene; rpb2: partial RNA polymerase II second largest subunit gene; tef1: partial translation elongation factor 1-alpha gene; tub2: partial β-tubulin gene.

Aveskamp MM, de Gruyter J, Woudenberg JHC, et al. (2010). Highlights of the Didymellaceae: A polyphasic approach to characterise Phoma and related pleosporalean genera. Studies in Mycology 65: 1–60.
Aveskamp MM, Verkley GJ, de Gruyter J, et al. (2009a). DNA phylogeny reveals polyphyly of Phoma section Peyronellaea and multiple taxonomic novelties. Mycologia 101: 363–382.
Aveskamp MM, Woudenberg JH, de Gruyter J, et al. (2009b). Development of taxon-specific sequence characterized amplified region (SCAR) markers based on actin sequences and DNA amplification fingerprinting (DAF): a case study in the Phoma exigua species complex. Molecular Plant Pathology 10: 403–414.
Berner D, Cavin C, Woudenberg JHC, et al. (2015). Assessment of Boeremia exigua var. rhapontica, as a biological control agent of Russian knapweed (Rhaponticum repens). Biological Control 81: 65–75.
Chen Q, Jiang JR, Zhang GZ, et al. (2015a). Resolving the Phoma enigma. Studies in Mycology 82: 137–217.
Marin-Felix Y, Groenewald JZ, Cai, L, et al. (2017). Genera of phytopathogenic fungi: GOPHY 1. Studies in Mycology xxxx.