Aspergillus fuscicans S. M. Romero, A. I. Romero, Barrera, V.A & Comerio, 2018

Romero, Stella M., Comerio, Ricardo M., Barrera, Viviana A. & Romero, Andrea I., 2018, Aspergillus fuscicans (Aspergillaceae, Eurotiales), a new species in section Usti from Argentinean semi-arid soil, Phytotaxa 343 (1), pp. 67-74 : 69-71

Aspergillus fuscicans S. M. Romero, A. I. Romero, Barrera, V.A & Comerio sp. nov.

MB 823159

( Fig. 1.A–H )

Type:— ARGENTINA. Catamarca: from Corral Quemado to Papachacra (27°07,545’S, 66°56,598’W, 2152 m elev), 10 January 2009, S.M. Romero ET1611 (Holotype BAFC 52653 dried culture). CaM and BenA gene sequences deposited at GenBank, accession numbers KY853415 and KY853416 ). BAFCcult 4564, culture ex type .

Etymology: fuscus –i, adjective, greyish brown to blackish, very dark blackish brown; – icans, suffix, indicates process of becoming or resemblance sometimes so close as to be almost identical; fusc – + – icans = fuscicans ; fuscicans : which becomes very dark blackish brown.

Diagnosis: Habitu morphologiaque A. usto et affinibus speciebus similis; ad A. calidoustum accedens , sed ab ea specie conidiis modice majoribus ac cellulis obtengentibus non modo irregulariter elongatis sed etiam oblongis oviformibusque recedens.

Description: Colonies on CYA, 25 ºC, 7 d, 29–35 mm, sulcate to plicate, greenish grey to dark grey (Buffy Olive, R. Pl. XXX; Fuscous to Chaetura Drab, R. Pl. XLVI) presenting narrow white margins, sporulation good to abundant, yellow pigment diffusing into the agar, exudate droplets scarce with yellowish to orange brown color; reverse yellow with brownish centers. After two incubation weeks, colonies becoming darker (Chaetura Drab to Fuscous–Black, R. Pl. XLVI) and reverse brownish yellow. At 37 ºC, 7 d, 25–34 mm diam., plicate, grey (Drab to Heir Brown, R. Pl. XLVI) presenting wide white to beige margins, good sporulation, occasionally yellow pigment diffusing into the agar, exudate droplets absent; reverse brownish). On CZ, 25 ºC, 7 d, 23–24 mm diam., sulcate, yellowish white to grey (near Heir Brown, R. Pl. XLVI), sporulation scarce, or abundant presenting narrow white margins, diffusible pigment absent, clear exudate droplets abundant at colony centers; reverse pale to yellow). On MEA, 25 ºC, 7 d, 37–50 mm diam., velutinous to rather floccose, grey (near Deep Grayish Olive, R. Pl. XLVI) with wide white margins, very good sporulation, diffusible pigment absent, exudate droplets abundant and clear; reverse brownish to brownish orange. The colonies become very dark blackish brown to black in two weeks of incubation (see detail in Fig. 1.C ). At 40 ºC, 7 d, 4–5 mm diam. At 42 ºC no growth. On BMEA, 25 °C, 7 d, 48–59 mm diam., velutinous, sometimes with an overlying white mycelium, grey (Deep Grayish Olive, R. PL. XLVI), very good sporulation describing a subtle annular pattern, wide white margins, diffusible pigment absent, exudate absent; reverse yellow to greenish. On OA, 25°C, 7 d, 40–50 mm diam., plane, very dark grey, almost black (Deep Greyish Olive to Chaetura Black, R. Pl. XLVI), very good sporulation, sometimes with an overlying white mycelium, soluble pigment light greenish yellow, abundant brownish exudate droplets; reverse yellow green to green (Citron Yellow to yellowish Citrine, R. Pl. XVI; Lettuce Green, R. Pl. V). On CREA, 25 ºC, 7 d, 14–21 mm diam., loose colorless mycelium, weak sporulation, neither acid nor base production). On YES, 25 ºC, 7 d, 40–42 mm diam., sulcate, rather floccose, sporulation medium to good, grey, (Light Grayish Olive to Deep Grayish Olive, R. Pl. XLVI), yellow pigment diffusing into the agar; reverse greyish yellow to vivid orange.

Teleomorph not observed. Conidial heads radiate. Conidiophores pigmented, brown but diminutive hyaline conidiophores when produced from aerial hyphae, 50–180 × 4–6 μm. Vesicles globose to pyriform, 10–16 μm diam., biseriate. Metulae 4–6 × 3 μm. Phialides 5–6 μm long. Conidia globose, coarsely roughened to echinulate, and even forming bars, 3.5–5 μm diam. Hülle cells hyaline, sparsely produced (a little more abundant in BMEA), irregularly elongated to oblong to ovoid, decreasing in number through successive subcultures.

Additional isolate examined: ARGENTINA, Catamarca, from Corral Quemado to Papachacra (27°07,545’S, 66°56,598’W, 2152 m elev), 25 August 2011, S.M. Romero ET4611, BAFCcult 4565 .

Molecular phylogenetic analyses: The CaM data set included 28 taxa and 472 characters and 28 and 449 for BenA . The CaM MP analysis yielded 6 optimal trees and a consensus strict tree of 833 steps with a consistency index CI = 0.51 and a retention index RI = 0.68 from 220 informative characters. The BenA MP analysis yielded six optimal trees and a consensus strict tree of 585 steps with a CI = 0.53, RI = 0.71 from 170 informative characters. The MP strict consensus trees based on the BenA and CaM dataset are shown in Fig 2 , together with the accession numbers of the query sequences and the 27 reference sequences, obtained from GenBank and Aspergillus versicolor as outgroup. The NJ analysis resulted in a phylogram, which had a similar topology as that of the MP analysis; the NJ bootstrap values are shown in the MP cladogram ( Figs. 2 and 3 ). In the BenA MP tree ( Fig. 2 ), A. fuscicans grouped with A. pseudodeflectus (MP = 100 % bs; NJ = 90 %) and these two were related with A. calidoustus (MP = 100 % bs; NJ = 90 %). In the CaM phylogenetic analysis ( Fig. 3 ), the three species grouped together in a polytomy (MP = 100 % bs; NJ = 98 %).

Figures

FIGURE 1. Aspergillus fuscicans. Colonies 7 d, 25 ºC.A. CYA. B. Reverse. C. MEA. C´. Colonies 30 d, 25 ºC. D–F. Conidiophores and conidia. G. Conidia. H–I. Hülle cells. Bars D–E, H–I = 20 μm, F–G = 10 μm.

FIGURE 2. Strict consensus phylogenetic cladogram constructed with maximum parsimony analysis with BenA sequences. MP and NJ bootstrap values>50% are shown above and below branches, respectively. Terminal nodes given as GenBank accession number and species name.

FIGURE 3. Strict consensus phylogenetic cladogram constructed with maximum parsimony analysis with CaM sequences. MP and NJ bootstrap values>50% are shown above and below branches, respectively. Terminal nodes given as GenBank accession number and species name.