Eryngium foetidum L. (Apiaceae) is a pungent leafy herb known as culantro. It is native to tropical America and the West Indies. In 2025, E. foetidum is widely present throughout Asia, tropical Africa, the Pacific Islands, and the warmer areas of southern Europe. It is used for gastronomy, medicinal applications, and other purposes in the pharmaceutical industry (Paul et al. 2011). In February 2019, a farm cultivating culantro in the municipality of Ananindeua (01°19'26.6" S 048°23'06.3" W), state of Pará, Brazil, reported a 5% incidence of plants affected (20 plants) by severe symptoms of nematode parasitism within a 20 m² area. The symptoms included underdevelopment of the shoot system, leaf yellowing followed by necrosis, and a high number of galls on the roots. Three symptomatic plants, along with the roots and surrounding soil, were randomly sampled and sent to the Nematology Laboratory (LabNema) at São Paulo State University (UNESP) for nematode identification. A total of 3,120 second-stage juveniles (J2) of Meloidogyne spp. were present in 100 cm³ of soil, and a total of 21,052 eggs and J2 were recovered per gram of root. The nematodes collected from the roots and rhizosphere of culantro were analyzed using morphological, biochemical and molecular methods. The perineal pattern of females (n = 15) exhibited a high dorsal arch with thick stripes and a trapezoidal shape. The labial region in males (n = 15) displayed a trapezoidal shape with distinct rings, prominent labial disc, transverse striations present, and basal nodules taller than wide (Taylor and Netscher 1974; Eisenback and Hirschmann 1981). The morphological characteristics of the adults were compatible to those originally described for M. incognita (Kofoid and White 1919) Chitwood 1949. The profile of 16 female obtained through isoenzyme electrophoresis was consistent with the I1 phenotype, which is characteristic of M. incognita (Esbenshade and Triantaphyllou 1985). Additionally, DNA was extracted from six females individually, in separate tubes. Amplification was performed using species-specific primers for M. incognita (Zijlstra et al. 2000) and for the 18S rDNA region (Holterman et al. 2006). Only 1,200 bp amplicons generated with the M. incognita-specific primers were obtained. Sequencing of 18S rDNA region confirmed the species as M. incognita with 100% of identity (haplotypes accession numbers OR001655 and OR001656). Koch's postulate confirmation research was conducted in a greenhouse under a temperature of 23°C, 73% relative humidity, and a 12-hour photoperiod. Seven culantro seedlings were individually transplanted into 5-liter pots filled with autoclaved substrate composed of sand, soil, and manure (4:1:1). Six seedlings were inoculated with 10 mL of a suspension containing 3,000 eggs and J2 juveniles (initial population density, Pi) from the original M. incognita population, whereas four seedlings served as uninoculated controls. After 90 days, the inoculated plants exhibited symptoms similar to those initially observed in the field, including numerous root galls and a substantial egg mass, in contrast to the healthy nonincubated plants. The average number of recovered J2 and eggs from seedlings roots and in 100 cm³ of soil was 209,700 (final population density, Pf), with a reproduction factor (Pf/Pi) of 69.90. Culantro is typically grown in succession with other vegetable host plants of M. incognita, such as lettuce, which facilitate the multiplication and dissemination of the nematode. This is the first report of M. incognita parasitizing E. foetidum in the Amazon region, serving as an alert for the practice of crop rotation.
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