Peru is the ninth exporter of coffee (Coffea arabica) in the world, and Amazonas is among its most important producing departments (INIA 2019). In July 2021, in the nursery of the "Instituto de Investigación para el Desarrollo Sustentable de Ceja de Selva", in Huambo district (6° 26' 11.19'' S; 77° 31' 24.18'' W), four-month-old coffee seedlings cv. Catimor with 0.5-2.0 cm brown concentric leaf spots and rotten stems, bearing white mycelial tufts and black sporodochia, were observed at 30% incidence. Infected seedlings were collected. Foliar sections of 2-3 mm with infected tissue were surfaced disinfected in 2% NaClO and transferred onto Petri plates containing potato dextrose agar medium (PDA). The plates were incubated at 25° C for 7 days. We obtained three isolates (INDES-AFHP61, INDES-AFHP62 and INDES-AFHP66) with similar morphology from different seedlings. Colonies (16-17 mm diam.) formed concentric rings with white aerial mycelium, giving rise to viscous and olivaceous dark green sporodochial conidiomata. Conidia (4.82-5.77 × 1.34-1.65 µm; n = 30) were cylindric, hyaline, smooth, and aseptate. These morphological features correspond to Paramyrothecium spp. (Lombard et al. 2016). The DNA of isolates was extracted using the Wizard® Purification Kit (Promega Corp., Madison, Wisconsin), and the internal transcribed spacer 1 and 2 intervening the 5.8S subunit rDNA region (Accession numbers: OM892830 to OM892832), and part of the second-largest subunit of the RNA polymerase II, the calmodulin and the β-tubulin genes (OM919453 to OM919461) were sequenced following Lombard et al. (2016). All sequences had a percent identity greater than or equal to 99% to corresponding sequences of the P. roridum type specimen (CBS 357.89). Additionally, a multilocus Maximum Likelihood phylogenetic analysis incorporating sequence data from previous relevant studies (Lombard et al. 2016; Pinruan et al. 2022) grouped our three isolates together with the type and other specimens of P. roridum in a strongly supported clade, confirming the species identification. To evaluate pathogenicity, four-month-old coffee seedlings cv. Catimor were sprayed with 10 mL of conidial suspensions at 1 x 106 /mL. A set of control seedlings were inoculated with sterile water. Seedlings were maintained in a humidity chamber at 25 °C. After 15 days brown concentric foliar spots, stem rotting, mycelial tufts and sporodochia (same symptoms and signs observed originally at the nursery) arose in the non-control seedlings. The pathogen was re-isolated on PDA, confirming P. roridum was the causal agent of leaf spot and stem rot diseases of coffee. Paramyrothecium roridum has wide geographic distribution and host range (Lombard et al. 2016). This pathogen was reported to infect C. arabica in Mexico and Coffea sp. in Colombia (Pelayo-Sánchez et al. 2017; Lombard et al. 2016; Huaman et al. 2021). It was also reported in Africa infecting soybeans (Haudenshield et al. 2018), in Brazil infecting Tectona grandis (Borges et al. 2018), in Egypt infecting strawberries (Soliman 2020), and in Malaysia infecting Eichhornia crassipes (Hassan et al. 2021). To the best of our knowledge, this is the first time P. roridum is reported on coffee in Peru.
Cultivation of yellow dragon fruit (Selenicereus megalanthus) in Peru has recently expanded (Verona-Ruiz et al. 2020). In August 2021, approximately 170 of 1,110 dragon fruit cuttings (15.3%) in the university's nursery (6°26'10'' S; 77°31'25'' W) showed basal rot symptoms. Initial symptoms included small brown spots on the base of stems, expanding towards the top that became soft and watery. All symptomatic plants eventually died, i.e., a severity of 100%. The disease was more prevalent on cuttings during the rooting phase than on well-established cuttings. We collected five symptomatic cuttings from throughout the nursery. Four sections of 1 × 1 cm2 of tissue adjacent to the diseased area were excised from each cutting, immersed for 1 min in 2% NaClO, rinsed twice with sterile distilled water, placed on potato dextrose agar (PDA) medium (four sections per Petri plate, five plates), and incubated at 25°C for 7 days. Morphologically similar mycelia grew from all sections, and five monosporic isolates were obtained, one per plate. Colonies grew fast, reaching 60 to 64 mm in 7 days, and produced violet-white cottony aerial mycelia with orange sporodochia on PDA, and abundant macro- and microconidia on synthetic nutrient-poor agar. Macroconidia were straight to slightly curved, typically with 2 to 3 septa, 16.6 to 23.3 × 1.7 to 3.7 µm (n = 30); microconidia were oval or kidney-shaped, and commonly hyaline, 6.7 to 16.4 × 2.5 to 4.7 µm (n = 40). Genomic DNA was extracted from isolate AFHP-100, then the ITS region and the TEF1 and RPB2 partial genes were amplified and sequenced (Accession numbers PP977433, OR437358, PP537149) following Gardes and Bruns (1993) and O'Donnell et al. (1998). We conducted a BLASTn search of ITS sequence against the NCBI "nr" database and local 'megablast' searches of TEF1 and RPB2 sequences against FUSARIUM-ID v.3.0 (Torres-Cruz et al. 2022). We found 100%, 98.19 to 99.84%, and 98.81 to 99.76% identities in ITS, TEF1, and RPB2 sequences, respectively, to the ex-epitype and other reference strains of Fusarium oxysporum (CBS 144134, NRRL26406, among others). A maximum likelihood phylogenetic analysis with a TEF1-RPB2 concatenated dataset with FUSARIUM-ID sequences also showed isolate AFHP-100 was F. oxysporum. A pathogenicity test was carried out by inoculating wounded healthy roots of three cuttings with submersion in a 5 × 106 conidia/ml suspension for 25 min. Then, the inoculated plants were planted in sterile soil. One cutting with wounded roots submerged in sterile water served as a control. In parallel, sterile soil was inoculated with 20 mL of the conidial suspension, and another three healthy cuttings were planted. A cutting planted in noninoculated soil also served as a control. Basal rot symptoms developed in all inoculated plants after 25 days. After re-isolation, the same fungus, corroborated based on micromorphology and TEF1 sequence (PP335689), was recovered, fulfilling Koch's postulates. The isolate was deposited in the KUELAP Herbarium (voucher KUELAP-3214), located and administered by the National University Toribio Rodriguez de Mendoza de Amazonas, in Chachapoyas, Peru. Fusarium oxysporum has been reported to cause basal stem rot in Bangladesh and Argentina (Mahmud et al. 2021; Wright et al. 2007), and stem blight in Malaysia (Mohd Hafifi et al. 2019) on dragon fruit. This is the first report of F. oxysporum causing basal rot in S. megalanthus in Peru. This fungus is among the most destructive plant pathogens, and the rapid expansion of the crop in Peru requires a comprehensive knowledge of the biotic factors influencing production. Therefore, this report is foundational to implementing proper control strategies.