ABSTRACT African iris ( Dietes bicolor ) is a rhizomatous ornamental plant widely used in landscape design. In 2025, plants showing chlorosis, reduced development, and root galls typical of Meloidogyne spp. were observed in a nursery in Santa Maria, Rio Grande do Sul, Brazil. Eggs and second‐stage juveniles (J2) were extracted from symptomatic roots, with an average density of 327 eggs and J2 per gram of root. Adult females collected from infected roots were used for isoenzymatic characterisation. Individual females were macerated in sucrose–Triton X‐100 buffer and analysed by polyacrylamide gel electrophoresis. The resulting esterase profile exhibited the characteristic J3 phenotype, identifying the population as Meloidogyne javanica . For molecular confirmation, DNA was extracted from single females, and PCR amplification using the species‐specific primers Fjav/Rjav consistently amplified the expected ~670 bp SCAR fragment. Pathogenicity was verified by inoculating healthy D. bicolor plants with 2,500 eggs. After 60 days, the reproduction factor was 2.1, and symptoms matched those observed in naturally infected plants, fulfilling Koch's postulates. This is the first report of M. javanica parasitizing D. bicolor in Brazil and, for the best of our knowledge, the first global record of this host–nematode association.
Júnior et al. (Thu,) studied this question.