Colletotrichum acaciae Y.X. Zhang, J.W. Chen, Z.L. Mai, & Manawas., sp. nov.

MycoBank number: MB; Index Fungorum number: IF; Facesoffungi number: FoF 10611,;

Etymology: Epithet refers to the host genus name Acacia.

Holotype: ZHKUCC 21-0077

Micromorphology: Associated with leaf spot of Acacia confusa Sexual morph: not observed. Asexual morph: Conidiaphores (8–) 9–12 × 3–5 μm (x̅ 10 × 4 μm, n=30) long, cylindrical or clavate, unbranded. Conidia 11–13 (–14) × 5–7 μm (x̅ 12 × 6 μm, n=50) long, one-cells, cylindrical, not appressoria produced.

Culture characteristics: Colonies on PDA attaining 67 diam in 7 days at 25 ℃, growth rate per day 5.00±0.50mm/d (n=4), white to grey, reverse dark grey to black at the centre, aerial mycelium dense and raise.

Material examined: China, Guangdong province, on Acacia confusa Merr Shenzhen Botanical Garden, 30th November 2020, J.W. Chen, Z.H. Zhang and C. Chen (dried cultures ZHKU 21-0070 holotype; ZHKU 21-0071 paratype), and living culture, ZHKUCC 21-0077 ex–holotype; ZHKUCC 21-0078 ex–paratype.

Notes: In the present study, two isolated developed a moderate support clade with C. endophytica (95% in ML and 80% in MP bootstrap values Fig. 42). Morphologically C. acaciae differ from C. endophytica in the colony and the size of conidia. The colony of C. endophytica is white to grey, reverse dark grey to black at the centre, conidia 13–19 (−21) × (4–) 5–6 μm (ave. 16× 5, n = 40) (Manamgoda et al. 2013). The colony of C. acaciae is white to grey, reverse dark grey at the centre with light yellow at the edge, and the conidia 10–13 (–15) × 5–7 μm (ave. 12.00 × 6.00 μm, n=50), which is significantly shorter and wider than C. endophytica. Therefore, based on multigene analysis of gapdh, act, chs-1 and tub2 sequence data and morphological evidence were introduced C. acaciae as a new species.

Fig. Colletotrichum acaciae (ZHKUCC 21-000077: Holotype) a, b. Upper and reverse view on PDA after seven days. c–e. Conidia. f–h.Conidiophores. Scale bars: f–h = 10 µm.