Curvularia australis (Alcorn) Y.P. Tan & R.G. Shivas, Australas. Pl. Pathol.

Manamgoda, Dimuthu S., Rossman, Amy Y., Castlebury, Lisa A., Chukeatirote, Ekachai & Hyde, Kevin D., 2015, A taxonomic and phylogenetic re-appraisal of the genus Curvularia (Pleosporaceae): human and plant pathogens, Phytotaxa 212 (3), pp. 175-198 : 184-187

Curvularia australis (Alcorn) Y.P. Tan & R.G. Shivas, Australas. Pl. Pathol. 43: 597 (2014). ( Fig. 2 )

Basionym : Bipolaris australis Alcorn, Mycotaxon 15: 38 (1982).

Type material:— AUSTRALIA. Queensland, on Sporobolus caroli , 12 May 1977, J. L. Alcorn 77134 (holotype of Bipolaris australis BRIP 12521); ibid. (isotype of Bipolaris australis IMI 261917!); ibid. (isotype of Bipolaris australis DAOM 38000!); Queensland, on Sporobolus mitchellii , 12 May 1977, J. L. Alcorn 77139 (paratype of Bipolaris australis BRIP 12525).

On Sporobolus mitchellii leaves, conidiophores (90–)110–234(–275) × 6–8 μm (av. = 172 SD = 62 n = 10; av. = 7, SD = 1, n = 10), arising occasionally singly or usually in groups, branched, septate, straight, geniculate at upper part, brown to pale reddish, lighter towards apex. Conidiogenous nodes dark brown, smooth. Conidia (33–)35–57(–69) × 9–15 μm (av. = 46 SD = 11 n = 32; av. = 12 SD = 3 n = 32), smooth-walled, straight or curved, subcylindrical to fusoid, sometimes narrowly clavate, tapering towards rounded apex, basal cell obconic, pale brown to mid reddish brown, 3–4-distoseptate (av. = 4). Hilum inconspicuous, germination bipolar.

Host s:— Sporobolus caroli , S. mitchellii , also reported from: Chloris gayana , Eragrostis cilianensis , Sporobolus elongatus , Thellungia advena ( Farr and Rossman 2014) .

Distribution:— Australia.

Notes:—This species was described by Alcorn (1982) and Tan et al. (2014) placed it in the genus Curvularia . It is closely related to Curvularia ovariicola as indicated in the phylogenetic tree provided herein ( Fig. 1 ). However, Curvularia ovariicola has longer conidia (50–80 μm) than C. australis . Therefore it is morphologically distinct from C. ovariicola .

Curvularia buchloës (Lefebvre & A.G. Johnson) Manamgoda, Rossman & K.D Hyde, Stud Mycol. 79: 279 (2014). ( Fig. 3 )

Basionym : Helminthosporium buchloës Lefebvre & Aar. G. Johnson, Mycologia 41: 204 (1949).

≡ Drechslera buchloës (Lefebvre & Aar. G. Johnson) Subram. & B.L. Jain, Curr. Sci. 35: 354 (1966).

≡ Bipolaris buchloës (Lefebvre & Aar.G. Johnson) Shoemaker, Can. J. Bot. 37: 882 (1959)

Type material:— USA. Kansas, Hayes, on Buchloë dactylidis , 18 June 1942, C. L Lefebvre (holotype of Helminthosporium buchloës BPI 428770!); ibid. culture (ex-holotype of Helminthosporium buchloës CBS 246.49!); Nebraska, Lincoln, on Buchloë dactylidis , 12 September 1940, R. Sprague (paratype of Helminthosporium buchloës BPI 428763!).

Leaf spots on Buchloë dactylidis . Straw coloured with dark blotches on both sides of leaf. Conidiophores (37–)41– 93(–110) × 4–6(–8) μm (av. = 67 SD = 26 n = 25; av. = 5 SD = 1 n = 25), arising occasionally singly or usually in groups, larger groups on brown stromata, unbranched, septate, straight, geniculate at upper part, olivaceous brown, lighter towards apex. Conidiogenous nodes dark brown, flattened from apex. Conidia (34–)40–69(–71) × (7–)8–12(– 15) μm (av. = 52 SD = 12 n = 30; av. = 10 SD = 2 n = 30), smooth-walled, straight or curved, ellipsoid to broadly ovoid, tapering towards rounded apex, basal cell rounded or truncate, hyaline when young, becoming pale brown when older, 3–8-distoseptate (av. = 5). Hilum inconspicuous, germination bipolar.

Hosts:— Buchloë dactylidis , also reported on Bouteloua curtipendula , B. gracilis , B. hirsuta ( Farr & Rossman 2014) .

Distribution:— USA, also reported from China ( Farr & Rossman 2014).

Additional material examined:— USA. Kansas, on Buchloë dactylidis , 4 July 1958, Karmer and Duffield ( BPI 428764 !) ; Kansas, Butler Co., Latham , on Buchloë dactyloides , 26 July 1957, C. T. Rogerson ( BPI 428765 !) ; Kansas, Riley Co., Manhattan , on Buchloë dactyloides , 22 June 1955, C. T. Rogerson ( BPI 428766 !) ; Kansas, Rooks Co., on Buchloë dactyloides , 1895, E. Bartholomew ( BPI 428767 !) ; Texas, College Station , on Buchloë dactyloides , 26 May 1946, C. L Lefebvre ( BPI 428768 !) ; Kansas. Rooks Co., on Buchloë dactyloides , 24 July 1895, E. Bartholomew ( BPI 428769 !) .

Notes:—The key morphological feature of this species is the production of conidiophores in groups on stroma that develop between fibrovascular bundles. Based on phylogenetic and morphological evidence, this species is placed in Curvularia ( Manamgoda et al. 2014) . This species is phylogenetically related to C. dactyloctenii and C. hawaiiensis . A sexual morph has not been reported for this species.

Curvularia cymbopogonis (C.W. Dodge) J.W. Groves & Skolko [as ‘cymbopogi’], Canadian Journal of Research, Section C 23: 96 (1945). ( Fig. 4 )

Basionym : Helminthosporium cymbopogonis C.W. Dodge [as ‘cymbopogi’], Ann. Mo. bot. Gdn 29: 139 (1942).

= Cochliobolus cymbopogonis J.A. Hall & Sivan., Trans. Br. mycol . Soc. 59(2): 315 (1972).

Type material:— SUDAN, on Sorghum , 27 November 1967, Fraser ( IMI 130402!).

Ascomata on Sorghum , black, ellipsoid (357–)411–727(–800) × (409–)425–575(–696) μm (av. = 569 SD = 158 n = 16; av. = 500 SD = 75 n = 16). Ostiolar neck (500–)551–1395(–1642) μm (av. = 973 SD = 422 n = 20) long (70–)104–146(–150) μm (av. = 120 SD = 26 n = 20) wide. Pseudoparaphyses numerous, hyaline, branched, filiform. Conidiophores and conidia occasionally on ascomatal outer wall, less frequently on ostiolar neck. Asci (210–)221– 335(–365) × (16–)18–22(–26) μm (av. = 278 SD = 57 n = 20; av. = 20 SD = 2 n = 20), bitunicate, cylindrical, clavate, short pedicellate. Ascospores (198–)201–305(–317) × 18–22 μm (av. = 253 SD = 52 n = 15; av. = 20 SD = 2 n = 15), filiform, hyaline, tapering towards end, spirally coiled inside ascus, 8–14 septate.

Asexual morph on Sorghum, Conidiophores up to 300 μm long. Conidia (30–)33–43(–46) × 13–19 μm (av. = 38 SD = 5 n = 30; av. = 16 SD = 3 n = 30), straight, sometimes curved, clavate to ellipsoid, pale brown, 4-distoseptate.

Hosts: Sorghum , also reported from Andropogon gabonensis , A. sambesi , A. tectorum , Bothriochloa caucasica , Cannabis indica , Coix lacryma , Cymbopogon citratus , C. confertiflorus , C. martinii , C. winterianus , Danthonia compressa, Hyparrhenia dissoluta, H. glabriuscula , H. rufa , Loudetia superba , Oryza sativa , Pinus sp. , Rottboellia exaltata , Zea mays ( Farr & Rossman 2014) .

Distribution:— Sudan, also reported from Africa, Brazil, Colombia, Cuba, Ghana, Japan, Jamaica, India, Malaysia, Nepal, Nigeria, Sierra Leone, USA, Venezuela, Zambia ( Farr & Rossman 2014).

Notes:—This species have a characteristic long ostiolar beak.According to the phylogenetic data of an authenticated culture, placement of this species in the genus Curvularia is confirmed ( Manamgoda et al. 2012a).

Figures

FIGURE 1. Phylogram generated for Curvularia from a maximum likelihood analysis based on the combined ITS, GPDH and TEF alignment. Maximum likelihood bootstrap values are shown above the branches. The thickened branches correspond to Bayesian posterior probability values more than 0.7. All ex-type cultures are printed in bold.

FIGURE 2. Curvularia australis (IMI 261917).A) Conidiophores on Sporobolus caroli leaf B) Conidiophores and conidia C–F) Conidia. (Scale bars A = 10 μm B = 20 μm C–F = 5μm).

FIGURE 3. Curvularia buchloës (BPI 428763, BPI 428756). A) Conidiophores on Buchloë dactylidis B) Conidia on Buchloë dactylidis C, D) Conidiophores E–K) Conidia. (Scale bars A = 500 μm b = 100 μm C = 10 μm D–K = 5 μm).

FIGURE 4. Curvularia cymbopogonis (IMI 130402). A) Ascomata produced in culture B) Cross section of ascomata C) Peridium wall with asci D) Ascus and pseudoparaphyses E–G) Asci H) Ascospore I) Conidia and conidiophores J–L) Conidia. (Scale bars A = 1000 μm B = 100 μm C–I = 10 μm J–L = 10 μm).