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 443.94NT

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 100167T

GU237707

EU880885

KY484605

-

KY484706

GU237501

Aveskamp et al. (2009b, 2010), Berner et al. (2015)

Bo. exigua var. pseudolilacis

CBS 101207T

GU237721

EU880874

KY484609

-

KY484710

GU237503

Aveskamp et al. (2009b, 2010), Berner et al. (2015)

Bo. exigua var. rhapontica

CBS 113651T

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 629.68T

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 3.18222T

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. T and 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.