First report of the occurrence of leaf spot caused by <i>Boeremia exigua</i> on <i>Khaya grandifoliola</i> and <i>K. senegalensis</i> in Brazil

African mahogany (Khaya spp.) is an arboreal species native to Africa. The economic importance of the genus due value its wood, used mainly in furniture industry and civil construction (Ribeiro et al., 2019). In Brazil, was introduced supply market demand for currently has estimated planted area 37,000ha a tree nursery located city Garça, São Paulo, approximately 20% seedlings K. grandifoliola senegalensis showed symptoms leaf spot 2020. spots usually started at edges leaflets rounded shape. lesions on displayed purple halo, dark brown grey centre (Figure 1), whilst were light centre, with 2). On both species, premature fall affected observed. Diseased tissues sent Forest Pathology Laboratory–FCA/UNESP indirect isolation done potato dextrose agar medium (PDA, 39 g/l). fungal colonies obtained initially cream colour, becoming over time 3). morphological characterisation spores revealed oval-shaped hyaline conidia measuring 6.3 (4.6–7.6) × 3.6 (2.0–5.2) μm (isolated from grandifoliola) 6.5 (4.1–7.6) 3.9 (2.3–5.5) senegalensis). formation pycnidia abundant around Khaya, however scarce formed PDA culture medium. These characteristics are similar those Phoma (Chen 2015). No reaction observed by NAOH test, indicating lack production antibiotic E (Boerema 2004). To confirm identity two isolates, we sequenced internal transcribed spacer (ITS), β-tubulin (Bt) actin (ACT) regions usingpreviously described methods (White 1990; Glass & Donaldson, 1995; Carbone Kohn, 1999). sequences three concatenated analysed maximum likelihood RaXML 1,000 bootstraps confirmed that isolates B. exigua 4). BLAST analysis resulted greater than 99.2% Bt 100% ITS ACT Boeremia exigua. deposited GenBank (Table 1). pathogenicity test performed eight-month-old using ten each Khaya. inoculated 5 mm diameter discs colonised previously isolated fungi. This inoculation method selected fungi kept humid chamber 25°C alternating photoperiod (12 hours dark). After 48 hours, necrosis region 5). pathogen successfully reisolated leaflets. control treatment, which received only fungal-free medium, no best our knowledge, this first report occurrence caused extends range known pathogens associated trees Khaya serves as basis development implementing disease management plans. authors would like thank CAPES (project number 001) Futuro Florestal Company all support.