Phyllosticta citrimaxima Wikee, Crous, K.D. Hyde & McKenzie, Stud in Mycol 76: 12. 2013
Index Fungorum: IF820634; Facesoffungi: FoFxxxxx; MycoBank: MB803675.
Pathogenic on fruit peel of Citrus maxima. Sexual morph: Unknown. Asexual morph: Conidiomata 150–160 × 120–130 μm, pycnidial (on PNA), forming after 4 d of incubation, black, superficial, globose. Peridium 20–30 μm thick, consist of 1–3 layers. Conidiogenous cells 3–5 × 1–2 μm, developing after 5 d, lining wall of pycnidium, phialidic, cylindrical, hyaline. Conidia 5(–8) × (3–)4(–7) μm, ellipsoidal, hyaline, 1-celled, smooth, surrounded by mucilaginous sheath, 1 μm thick, bearing a single, apical appendage, 2–16 μm long.
Culture characteristics: On OA, colonies flat, with irregular margin, initially hyaline with abundant mycelium, gradually becoming greenish after 2–3 d. On MEA colonies woolly, irregular, initially white with abundant mycelium, gradually becoming greenish to dark green after 2–3 d with white hyphae on the undulate margin, eventually turning black; reverse dark green to black. After 25 d in the dark at 27 ºC the colony covered the whole plate. On PDA, colonies were flat, rather fast growing, initially white with abundant mycelium, gradually becoming greenish to dark green after 2–3 d, with white hyphae at the margin, eventually turning black; reverse black and after 14 d in the dark at 27 ºC colony covered the whole plate.
Representative isolate: Thailand, Chiang Rai, Weing Khaen, on fruit peel of Citrus maxima, Jun. 2011, S. Wikee, holotype MFLU 13-0001, CPC 20276 = MFLUCC10-0137 = CBS 136059 (ex-type culture).
Host: Citrus maxima (Wikee et al. 2013).
Known distribution: Thailand (Wikee et al. 2013).
GenBank Numbers: ITS - KF170304, LSU - KF206229, TEF - KF289222, ACT - KF289300, GPDH - KF289157.
Notes: Phyllosticta citrimaxima was isolated from tan spots on the fruit surface of Citrus maxima, which is grown as an economically important crop in Thailand and Asia. Recently, P. citriasiana, and P. citrichinaensis were described from Citrus maxima in Vietnam and China (Wulandari et al. 2009, Wang et al. 2012), and P. citribraziliensis from Brazil (Glienke et al. 2011). Phyllosticta citrimaxima is well supported phylogenetically (Fig. 1). Phyllosticta citrimaxima produces smaller conidia (5–8 × 3–7 μm) than P. citricarpa (11–12 × 6–8 μm), P. citriasiana (12–14 × 6–7 μm), P. capitalensis (11–12 × 6–7 μm), P. citribraziliensis (10–12 × 6–7 μm) and P. citrichinaensis (8–12 × 6–9 μm), and has longer apical appendages (2–16 μm) than any of these four species, except P. citrichinaensis (14–26 μm).
Wikee S, Lombard L, Nakashima C, Motohashi K, Chukeatirote E, Cheewangkoon R, McKenzie EHC, Hyde KD, Crous PW (2013) A phylogenetic re-evaluation of Phyllosticta (Botryosphaeriales). Studies in Mycology 76: 1–29.