Fusarium tanahbumbuense Sand. - Den., L. Lombard, Kema & Crous , Persoonia 43: 63 (2019) Pathogenic fungi (Sordariomycetes) associated with annual and perennial crops in Northern Thailand Fallahi, Maryam Armand, Alireza Al-Otibi, Fatimah Hyde, Kevin D. Jayawardena, Ruvishika S. MycoKeys 2025 2025-05-09 117 191 265 6JSVC Sand. - Den., L. Lombard, Kema & Crous Sand. - Den., L. Lombard, Kema & Crous Dothideomycetes Botryosphaeriaceae Fusarium Fungi Botryosphaeriales Ascomycota species tanahbumbuense   Fig. 24   Description. Pathogenic to durian (  Durio zibethinus) and pepper (  Capsicum annuum), and causes small, water-soaked lesions on leaves and stems that enlarge into necrotic spots with dark margins, potentially leading to defoliation and stem girdling under favorable, humid conditions. Sexual morph not observed. Conidiophores on aerial mycelium septate, irregular, verticillately branched. Conidiogenous cells mono- or polyphialidic, subulate or subcylindrical, smooth and thin-walled, 7–24 × 2–4 µm (mean = 13 × 3 µm, n = 15). Conidia on aerial mycelium, ellipsoidal to falcate, smooth and thin-walled, 1–3 septate, 7–27 × 2–4 µm (mean = 33 × 3 µm, n = 30). Sporodochia are formed plentifully on CLA after 7 days and have a pale orange color. Conidia on sporodochia falcate, produced by both mono- and polyphialides, apical cells conical to papillate, basal cells indistinct or foot-shaped, 3–5 - septate, 26–38 × 2–3.7 µm (mean = 33 × 3 µm, n = 30). Chlamydospores are absent.   Figure 24.   Fusarium tanahbumbuense(  MFLUCC24-0231) aleaf spots on durian bstem and leaf spots on pepper cfront, and dback views of the colony after 10 days of growth on PDAat 25 ° C espordochium f – gspordochium conidia h, iconidiophores and conidiogenous cells. jaerial conidia. Scale bars: 20 μm.   Culture characteristics. Colonies on PDAreach 50 mmin diameter after 7 days of growth at 25 ° C in the dark, cottony and rosy buff in the center, becoming white towards the margin, with moderate aerial mycelium, and appearing wet with age. The reverse is rosy buff, becoming white towards the margins.   Material examined.   Thailand• Chiang Rai, Mueang Chiang Rai District, Doi Hang, on leaf spot on durian (  Durio zibethinus),  December 2022, Maryam Fallahi, dried culture MF 31-1 (  MFLU24-0248), living culture  MFLUCC24-0231•  Amphoe Mueang Sakon Nakhon, Chang Wat Sakon Nakhon, leaf spot on pepper (  Capsicum annuum),  February 2023, Maryam Fallahi, dried culture MF 145-1 (  MFLU24-0250), living culture  MFLUCC24-0247.   Notes. In the present study, strains  MFLUCC24-0231and  MFLUCC24-0247clustered with  Fusarium tanahbumbuense(InaCC: F 965, ex-type) in  F. incarnatumcomplex with 100 % ML, 100 % IQ bootstrap support, and 1.0 BYPP(Fig. 21). The base pair differences between  F. tanahbumbuensestrains  MFLUCC24-0231and ex-type InaCC: F 965 revealed a 0.36 % (2 / 541 bp) difference in tef 1, a 0.71 % (6 / 838 bp) difference in rpb 2, and a 0.27 % (2 / 742 bp) difference in rpb 1. The base pair differences between  F. tanahbumbuense(  MFLUCC24-0247) and  F. tanahbumbuense(InaCC: F 965, ex-type) revealed a 0.42 % (2 / 470 bp) difference in tef 1, a 0.62 % (8 / 801 bp) difference in rpb 2, and a 0.27 % (2 / 742 bp) difference in rpb 1. Fusarium tanahbumbuensewas first reported from Indonesiaon an infected pseudostem of  Musasp.( Maryani et al. 2019 a). This study provides two new hosts and geographical records for  F. tanahbumbuenseon durian and pepper. 5147564314 on leaf spot on durian (Durio zibethinus) 2022-12 MFLU, MFLUCC Maryam Fallahi Thailand Mueang Chiang Rai District Doi Hang MFLU 24-0248, MFLUCC 24-0231 1 Chiang Rai 5147564316 leaf spot on pepper (Capsicum annuum) 2023-02 MFLU, MFLUCC Maryam Fallahi Thailand Amphoe Mueang Sakon Nakhon Chang Wat Sakon Nakhon Amphoe Mueang MFLU 24-0250, MFLUCC 24-0247 1 Chiang Rai