Alternaria ouedrighensis, A. Berraf-Tebbal, A. E. Mahamedi, F. Lamghari, E. Hakalova & Y. Djellid, 2025

Alternaria ouedrighensis, A. Berraf-Tebbal, A. E. Mahamedi, F. Lamghari, E. Hakalova & Y. Djellid sp. nov.

Fig. 4 View Figure 4

Type.

Algeria • Biskra Province (34°44'16.0152"N, 5°22'10.1064"E), on symptomatic leaf of Phoenix dactylifera L. 2017, Y Djellid ( MEND-F-1168 , holotype), ex-type culture CBS 152587 GoogleMaps .

Etymology.

Named after the valley of Oued Righ from which the fungus was collected.

Description.

Colonies on Potato dextrose agar (PDA) reaching 51 mm diam. after 7 d at 25 ° C, circular with concentric zonation of the growth, cottony with dense hyphae, dark green, reverse dark brown, with a white halo at the edge. Minimum temperature for growth 5 ° C, optimum 25 ° C, maximum 37 ° C. On PDA media (Fig. 4 View Figure 4 ), conidiophores arising directly from lateral of aerial hyphae, straight or curved, geniculate sympodial proliferation, verruculose thick-walled, with up to 12 – septate, unbranched or with up to three branches, light to dark brown; Conidia solitary, ovoid to subcylindrical, (11.4 –) 15.3 – 17.7 (– 24.1) × (7.7 –) 9.9 – 10.9 (– 12.9) μm (av. 16.5 ± 3.4 × 10.4 ± 1.4), light brown to dark, rigid, and thickened transverse septa, 1–3 transverse septa, and 0–1 longitudinal or oblique septa per transverse segment; these primary conidia produce secondary conidiophores that consist of a subapical extension from the conidial body. Sexual morph not observed.

Note.

Phylogenetically A. ouedrighensis formed a sister branch with A. embellisia , A. chlamydosporigena , A. radicicola and A. tellustris in Embellisia section with 100 % ML / 100 % MP bootstrap support. Alternaria ouedrighensis sp. nov. is different from its sister species A. radicicola , A. embellisia and A. tellustris based on sequences derived from five genes (Fig. 2 View Figure 2 ). After conducting a nucleotide pairwise comparison as recommended by Jeewon and Hyde (2016), the present species can be readily distinguished from the closet species A. radicicola , A. embellisia and A. tellustris constructed on any of the LSU, ITS, GAPDH, RPB 2 and TEF 1 genes, which has 3 bp difference (1 %, no gap) in the ITS region, 6 bp (2 %, no gap) in GAPDH, 16 pb (2 %, no gap) in RPB 2 and 15 bp (11 %, 14 gap) in TEF 1 when compared with A. radicicola , 1 bp (1 %, no gap) in LSU, 6 bp (2 %, no gap) in ITS, 24 bp (4 %, 1 gap) in GAPDH, 17 bp (2 %, 1 gap) in RPB 2, and 17 bp (11 %, 13 gaps) in TEF 1 when compared with A. embellisia , and 1 bp (1 %, no gap) in LSU, 3 bp (1 %, no gap) in ITS, 12 bp (2 %, 1 gap) in GAPDH, 17 bp (2 %, no gap) in RPB 2 and 13 bp (9 %, 14 gaps) in TEF 1 with sister species A. tellustris .

Morphologically, A. ouedrighensis (Fig. 4 View Figure 4 ) is distinct from the closest species A. embellisia in conidial body size. Alternaria ouedrighensis has conidia shorter and wider (11.4–24.1 × 7.7–12.9 μm; av. 16.5 ± 3.4 × 10.4 ± 1.4 µm) than those of A. radicicola (20–38 × 7–10 µm; Bessadat et al. 2025) and A. embellisia (19.18–36.2 × 2.55–5.74 µm; av. 12.64 × 4.34 µm; Delgado Ortiz et al. 2019). In addition, the conidia of A. ouedrighensis present fewer transverse septa (1–3 transverse septa) than those of A. radicicola (3–5 transverse septa) and A. embellisia (2 – 6 transverse septa). However, A. ouedrighensis presents fewer longitudinal septa (0–1 septum) compared to A. embellisia (1 – 2 septa).