Neptunomyces aureus M. Goncalves , T. Vicente & A. Alves. Portugal

Goncalves, Micael F. M., Vicente, Tania F. L., Esteves, Ana C. & Alves, Artur, 2019, Neptunomyces aureus gen. et sp. nov. (Didymosphaeriaceae, Pleosporales) isolated from algae in Ria de Aveiro, Portugal, MycoKeys 60, pp. 31-44 : 31

Neptunomyces aureus M. Goncalves, T. Vicente & A. Alves. Portugal sp. nov. Fig. 4

Type.

Portugal, Ria de Aveiro (40°40'38"N, 8°42'21"W), isolated from Gracilaria gracilis , 26th September 2018, M. Gonçalves, (holotype: a dried culture sporulating on pine needles AVE-F-1; ex-type living culture, MUM 19.38 = CMG 10A).

Etymology.

Referring to the golden yellow conidia.

Diagnosis.

Phylogenetic analysis based on the ITS, ITS and tub2 and ITS and tef1-α dataset considered in the present study clustered the retrieved strains in a monophyletic lineage in the family Didymosphaeriaceae . Therefore, a new genus Neptunomyces gen. nov., and a new species Neptunomyces aureus sp. nov. are here proposed.

Description.

Mycelium smooth, white, 2-3 μm wide hyphae. Hyphae thick-walled, smooth, hyaline and rarely with nucleus. Conidiomata aggregated or solitary, globose to subglobose, dark brown, immersed or rarely superficial. Conidiomata wall pseudoparenchymatous. Conidiophores reduced to ampulliform to subcylindrical, hyaline, smooth conidiogenous cells (mean ± S.D. = 5.2 ± 0.3 × 2.0 ± 0.6 μm, n = 20). Conidia solitary, subcylindrical with rounded apices, aseptate, initially hyaline, smooth, becoming golden yellow (mean ± S.D. = 7.0 ± 0.6 × 2.7 ± 0.2 μm, n = 100). Sexual morph unknown.

Culture characteristics.

On 2 weeks old PDA and OA plates, at 25 °C, colonies growing to 50 mm in diameter, regular and above and a little immersed into agar. PDA obverse white near the center getting flesh orange towards the borders; reverse buff orange in the center and lighter in periphery. OA obverse skimmed milk white; reverse snow white. On 2 weeks old MEA plates, at 25 °C, colonies growing to 44 mm in diameter, regular and above and a little immersed into agar. Obverse orange-colored white; reverse reddish orange in the center and ochre yellow in periphery. At 35 °C, there was no growth in any media tested.

Distribution.

Estuary Ria de Aveiro, Portugal

Additional specimens examined.

Portugal, Ria de Aveiro (Table 1 ), isolated from Ulva sp., Enteromorpha intestinalis and Enteromorpha sp. (Supp. material 1: Table S1). M. Gonçalves, living cultures CMG 11, CMG 12, CMG 13 and CMG 14.

Notes.

Neptunomyces aureus clustered in a distinct lineage in the family Didymosphaeriaceae with high p-distances (= 0.07) of nucleotide sites among the two-loci sequences (ITS and tef1-α) with closest genus Xenocamarosporium . Although the morphology of conidiomata, conidiomata wall and conidiogenous cells can be very similar in the genera of this family, conidial morphology distinguishes Neptunomyces from Xenocamarosporium (Table 2 ).

Figures

Figure 4. Neptunomyces aureus (MUM 19.38). A, B Colony after 2 weeks at 25 ° C on PDA (obverse and reverse) C, D colony after 2 weeks at 25 ° C on MEA (obverse and reverse) E, F colony after 2 weeks at 25 ° C on OA (obverse and reverse) G, H conidiomata after 1 month at 25 ° C on pine needles and PDA. I, J conidiogenous cells K conidia. Scale bars: 2.5 μm.