Fusarium sulawesiense Sand.-Den., L. Lombard, Kema & Crous [as ‘ sulawense’], Persoonia 43: 65 (2019)

Fig. 23

Description.

Pathogenic to Mangosteen ( Garcinia mangostana) and causes small, water-soaked lesions on the fruit surface; lesions may appear slightly sunken and surrounded by a yellow or brown halo. Sexual morph not observed. Conidiophores on aerial mycelium plentiful, septate, verticillately or irregularly branched. Conidiogenous cells mono- or polyphialidic, sub-cylindrical, smooth, thin-walled, 8–20 × 1.5–4 µm (mean = 14 × 3 μm, n = 20). Conidia on aerial mycelium falcate or fusiform, 1–5 septate: 1 - septate conidia 8.5–20 × 2.2–4.7 µm (mean = 13.5 × 3.5 μm, n = 30), 5 - septate conidia 32–42 × 2.5–4.5 µm (mean = 35 × 4.1 μm, n = 30). Sporodochia are formed on CLA after 7 days and have a pale orange color. Macroconidia in sporodochia falcate, with apical cells gently curved, papillate, and basal cells slightly curved, foot-shaped, 3–7 septate, 30–40.5 × 2.5–4 µm (mean = 33 × 3.6 μm, n = 30). Chlamydospores are absent.

Culture characteristics.

Colonies on PDA reach 65 mm in diameter after 7 days of growth at 25 ° C in the dark, cottony, white to pale pink, yellow, or pale brown in the center, and with a radial orange color on the reverse.

Material examined.

Thailand • Chiang Rai, Mueang Chiang Rai District, Ban Du, on fruit rot of Mangosteen ( Garcinia mangostana), June 2023, Maryam Fallahi, dried culture L 5-6 (MFLU 24-0253), living culture, MFLUCC 24-0250 .

Notes.

Based on phylogenetic analysis, MFLUCC 24-0250 clustered with Fusarium sulawesiense (InaCC F 940, holotype) in F. incarnatum species complex with 67 % ML, 97 % IQ bootstrap support, and 0.99 BYPP (Fig. 21). The base pair differences between F. sulawesiense strains MFLUCC 24-0250 and the ex-type InaCC F 940 revealed a 0.36 % (2 / 554 bp) difference in tef 1 and no difference in rpb 2. The sequence of the rpb 1 gene is not available for the type strain. Fusarium sulawesiense (MFLUCC 24-0250) is similar to the ex-type strain (InaCC F 964). However, the ex-type strain did not describe septate conidia (Maryani et al. 2019 b). Fusarium sulawesiense was first reported from bananas in Indonesia (Maryani et al. 2019 b). In Thailand, it was isolated from pineapple (Abeywickrama et al. 2023), and this study provides the first host association of F. sulawesiense with Mangosteen ( Garcinia mangostana).