Bipolaris Shoemaker, Can. J. Bot. 33:882(1959)

For synonyms see Index Fungorum (2018)



Species of Bipolaris are cosmopolitan and distributed throughout a broad range of environments. Bipolaris species are pathogens, saprobes or endophytes of a wide range of hosts (Hyde et al. 2014). Bipolaris oryzae critically damaged the rice cultivation in Bengal province in India and caused a devastating famine during 1943–1944 (Scheffer 1997; Hyde et al. 2014). Although not resulting in human starvation, Southern corn leaf blight caused by Bipolaris maydis in the 1970s resulted in catastrophic losses in maize crops in the USA and UK (Manamgoda et al. 2014). Bipolaris sorokiniana was confirmed as the most economically important foliar pathogen in warm areas in the conference “Wheat for the national warm areas” held in Brazil in 1990 (Hyde et al. 2014). Some Bipolaris species are pathogenic to humans (El-Khizzi et al. 2010). Transferring agricultural commodities including plants and seeds across geographical borders without proper quarantine implementation may have resulted in the worldwide distribution of common phytopathogenic species of Bipolaris (Farr and Rossman 2018; Manamgoda et al. 2014).


ClassificationDothideomycetes, Pleosporomycetidae, Pleosporales, Pleosporaceae

Type speciesBipolaris maydis (Y.Nisik. & C. Miyake) Shoemaker, Can. J. Bot. 33:882(1959)

Distribution – Worldwide

Disease Symptoms –Leaf spots, leaf blights, melting outs, common root rot, foot rot

            Small brown-red water-soaked spots on leaves can be observed. Subsequently, the disease area may turn into black/brown elliptical or fusiform lesions with grey to brown centers. On a fully developed lesion concentric rings can be observed (Lin et al. 2012; Ahmadpour et al. 2012). Decaying leaves with purple/brown lesions are observed in melting out disease (Watkins 1989). Brown to black lesions on primary and secondary roots, brown discolouration of crowns, yellowing of plants and browning of sub-crown internode can be observed in common root rot disease (Arabi et al. 2013). In foot rot disease, dark brown lesions on the sub-crown are caused. These lesions will eventually spread to encompass the entire sub-crown internode (Smiley and Patterson 1996).

HostsPoaceae, including rice, maize, wheat and sorghum (Manamgoda et al. 2014). Species of Bipolaris are also recorded from at least 60 other plant genera in Anacardiaceae, Araceae, Euphorbiaceae, Fabaceae, Malvaceae, Rutaceae and Zingiberaceae as either saprobes or pathogens (Manamgoda et al. 2011; Ariyawansa et al. 2015a).

Morphological based identification and diversity

Correct species identification in this genus has always proven difficult, mostly relying on morphology and plant host association. Studies on the morphology of the sexual morph of most Bipolaris are lacking due to difficulties to induce this morph in culture or to find it in nature (Manamgoda et al. 2014). Manamgoda et al. (2014) revised the genus based on DNA sequence data derived from living cultures of fresh isolates, available ex-type cultures from worldwide collections and observation of type and additional specimens. They accepted 47 species in Bipolaris and clarified the taxonomy, host associations, geographic distributions and species synonymy while epi- or neotypes were designated (Ariyawansa et al. 2015a). Currently, there are 131 species epithets in Index Fungorum (; retrieved 24 March 2018). Wijayawardene et al. (2017b) estimated there were 121 species in this genus. In a recent study Marin-Felix et al. (2017) has included 40 accepted Bipolaris species to their phylogenetic analyses. To properly delineate these species, phylogenetic studies using ITS, GAPDH and TEF1- α sequences were recently performed (Manamgoda et al. 2014, 2015; Marin-Felix et al. 2017).

Identification based on morphology alone is imperfect since many species have overlapping characters. The genus is morphologically similar to Curvularia and distinguishing these two genera can be problematic (Manamgoda et al. 2011, 2014). Both genera contain species with straight or curved conidia, but in Bipolaris the curvature is continuous throughout the length of the conidium, while the conidia of Curvularia have intermediate cells inordinately enlarged which contributes to their curvature (Manamgoda et al. 2011, 2014; Marin-Felix et al. 2017). Conidia in Bipolaris are usually longer than in Curvularia. Also, the presence of stromata in some species of Curvularia is significant whereas this feature is not observed in Bipolaris (Manamgoda et al. 2014; Marin-Felix et al. 2017).

Molecular based identification and diversity

To achieve better generic and species delimitation, phylogenetic studies using ITS, GAPDH and TEF1-α were recently performed (Manamgoda et al. 2014; Hyde et al. 2014; Marin-Felix et al. 2017). Phylogenetic studies based on these loci made it possible to reallocate species of Cochliobolus (sexual morph) to either Bipolaris or Curvularia (Marin-Felix et al. 2017). We update the phylogeny of Bipolaris based on analyses of a combined ITS, GAPDH and TEF1-α sequence data and it is in accordance with previous studies. Sequences obtained were from available ex-epitype, ex-isotype, ex-isolectotype, ex-paratype, ex-syntype and ex-type strains cultures.

Recommended genetic marker (genus level) – LSU

Recommended genetic markers (species level) – ITS, GAPDH and TEF


Accepted number of species: There are 130 species epithets in Index Fungorum (2018) under this genus. However, only 40 are accepted.

References: Manamgoda et al. 2011, 2014, Ariyawansa et al. 2015a, Marin-Felix et al. 2017 (morphology, phylogeny).

Table Bipolaris. Details of the isolates used in the phylogenetic analyses. Ex-type (ex-epitype) strains are in bold and marked with an * and voucher strains are in bold.

Species Isolate ITS GAPDH TEF1- α
Bipolaris austrostipae BRIP 12490* KX452442 KX452408 KX452459
B. axonopicola BRIP 11740* KX452443 KX452409 KX452460
B. bamagaensis BRIP 13577* KX452445 KX452411 KX452462
B. bicolour CPC 28811 MF490804 MF490826 MF490848
B. bicolour CPC 28825 MF490805 MF490827 MF490849
B. bicolour CBS 690.96 KJ909762 KM042893 KM093776
B. brachiariae CPC 28819* MF490806 MF490828 MF490850
B. brachiariae CPC 28820 MF490807 MF490829 MF490851
B. chloridis BRIP 10965* KJ415523 KJ415423 KJ415472
B. clavata BRIP 12530* KJ415524 KJ415422 KJ415471
B. coffeana BRIP 14845* KJ415525 KJ415421 KJ415470
B. cookie AR 5185 KJ922391 KM034833 KM093777
B. crotonis BRIP 14838 KJ415526 KJ415420 KJ415479
B. cynodontis CBS 109894 KJ909767 KM034838 KM093782
B. drechsleri CBS 136207* KF500530 KF500533 KM093760
B. gossypina BRIP 14840* KJ415528 KJ415418 KJ415467
B. heliconiae BRIP 17186* KJ415530 KJ415417 KJ415465
B. heveae CBS 241.92 KJ909763 KM034843 KM093791
B. luttrellii BRIP 14643* AF071350 AF081402 AF071350
B. maydis CPC 28823 MF490808 MF490830 MF490852
B. maydis CBS 137271* AF071325 KM034846 KM093794
B. microlaenae CBS 280.91* JN601032 JN600974 JN601017
B. microstegii CBS 132550* JX089579 JX089575 KM093756
B. oryzae CPC 28826 MF490809 MF490831 MF490853
B. oryzae CPC 28828 MF490810 MF490832 MF490854
B. oryzae MFLUCC 10-0715* JX256416 JX276430 JX266585
B. panici-miliacei CBS 199.29* KJ909773 KM042896 KM093788
B. peregianensis BRIP 12790* JN601034 JN600977 JN601022
B. pluriseptata BRIP 14839* KJ415532 KJ415414 KJ415461
B. sacchari ICMP 6227 KJ922386 KM034842 KM093785
B. saccharicola CBS 155.26* KY905674 KY905686 KY905694
B. saccharicola CBS 324.64 HE792932 KY905692 KY905699
B. saccharicola CBS 325.64 KY905675 KY905687 KY905695
B. salkadehensis Bi 1* AB675490 AB675490 AB675490
B. salviniae BRIP 16571* KJ415535 KJ415411 KJ415457
B. secalis BRIP 14453* KJ415537 KJ415409 KJ415455
B. setariae CPC 28802 MF490811 MF490833 MF490811
B. setariae CBS 141.31 EF452444 EF513206 EF452444
B. shoemaker BRIP 15929* KX452453 KX452419 KX452470
B. simmondsii BRIP 12030* KX452454 KX452420 KX452471
B. sivanesaniana BRIP 15847* KX452455 KX452421 KX452472
B. sorokiniana CPC 28832 MF490812 MF490834 MF490855
B. sorokiniana CBS 110.14 KJ922381 KM034822 KM093763
B. subramanianii BRIP 16226* KX452457 KX452423 KX452474
B. urochloae ATCC 58317 KJ922389 KM230396 KM093770
B. variabilis CBS 127716* KY905676 KY905688 KY905696
B. variabilis CBS 127736 KY905677 KY905689 KY905677
B. victoriae CBS 327.64* KJ909778 KM034811 KM093748
B. woodii BRIP 12239* KX452458 KX452424 KX452475
B. yamadae CPC 28807 MF490813 MF490835 MF490856
B. yamadae CBS 202.29* KJ909779 KM034830 KM093773
B. yamadae CBS 127087 (neotype of B. euphorbiae) KY905673 KY905685 KY905693
B. zeae BRIP 11512IsoP* KJ415538 KJ415408 KJ415454
B. zeicola FIP 532* KM230398 KM034815 KM093752
Curvularia lunata CBS 730.96* JX256429 JX276441 JX266596
C. sorghina BRIP 15900* KJ415558 KJ415388 KJ415435
C. subpapendorfii CBS 656.74* KJ909777 KM061791 KM196585

Fig Phylogenetic tree generated by maximum likelihood analysis of combined ITS, GAPDH and TEF1- α sequence data of Bipolaris species. Related sequences were obtained from GenBank. Fifty-seven strains are included in the analyses, which comprises 1998 characters including gaps. Tree was rooted with Curvularia subpapendorfii (CBS 656.74), C. lunata (CBS 730.96) and C. sorghina (BRIP 15900). The best scoring RAxML tree with a final likelihood value of -7757.628604 is presented. The matrix had 492 distinct alignment patterns, with 10.59% of undetermined characters or gaps. Estimated base frequencies were as follows; A = 0.232326, C = 0.300959, G = 0.235960, T = 0.230755; substitution rates AC = 0.597533, AG = 2.227202, AT = 0.791120, CG = 0.627286, CT = 4.571166, GT = 1.000000; gamma distribution shape parameter α = 0.779269. RAxML bootstrap support values ≥60% (BT) are shown respectively near the nodes. The scale bar indicates 0.02 changes. T, ET, IsoT, IsoLT, IsoPT, LT and NT indicate ex-type, ex-epitype, ex-isotype, ex-isolectotype, ex-isoparatype, ex-lectotype and ex-neotype strains, respectively.

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