Potato is the third most important crop in the world after rice and wheat, with a great social and economic importance in Portugal as it is grown throughout the country, including the archipelagos of Madeira and the Azores. The tropical root-knot nematode (RKN) Meloidogyne luci is a polyphagous species with many of its host plants having economic importance and the ability to survive in temperate regions, which pose a risk to agricultural production. In 2019, M. luci was detected from soil samples collected from the council of Santo António in Pico Island (Azores). Bioassays were carried out to obtain females, egg masses, and second-stage juveniles to characterize this isolate morphologically, biochemically, and molecularly. The observed morphological features and morphometrics showed high similarity and consistency with previous descriptions. Concerning the biochemical characterization, the esterase (EST) phenotype displayed a pattern with three bands similar to the one previously described for M. luci and distinct from M. ethiopica. Regarding the molecular analysis, an 1800 bp region of the mitochondrial DNA between cytochrome oxidase subunit II (COII) and 16S rRNA genes was analyzed and the phylogenetic tree revealed that the isolate grouped with M. luci isolates (99.17%). This is the first report of M. luci parasitizing potato in the Azores islands, contributing additional information on the distribution of this plant-parasitic nematode.

Plant-parasitic nematodes (PPN) are an economically important group of plant pests present throughout the world. In particular, root-knot nematodes (RKN), sedentary endoparasites of a wide variety of economically important hosts with the ability to survive in temperate regions. During 2020–2021 an extensive survey of Meloidogyne spp. was undertaken on the island of São Miguel Azores, Portugal. A total of 80 samples comprising 23 species of plants were collected from 13 localities in 4 districts of the island. Samples included field and greenhouse vegetable crops. Bioassays were carried out to obtain females and juveniles for morphological and biochemical characterization of the isolates. The observed morphological features showed high similarity and consistency with previous descriptions of the genus. Concerning the biochemical characterization, the esterase (EST) phenotype displayed the patterns described for M. incognita, M. arenaria, and M. javanica. Meloidogyne incognita was found to be the most prevalent species with respect to both natural host range and geographical distribution, followed by M. arenaria and M. javanica. This is the first field survey that assesses the species of root-knot nematodes associated with horticultural crops in the Azores Island, contributing additional information on the distribution of this genus.

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