Susceptibility of Pitaya genotypes to Meloidogyne incognita and M. javanica: implications for nematode management in Brazil

Abstract

Pitaya (Selenicereus spp., Cactaceae) has gained popularity among fruit consumers due to its distinctive flavor, shape, color, as well as vitamin C and B contents. However, recent studies have reported pitaya as a host for economically important nematodes of the genus Meloidogyne. These nematodes exhibit a wide host range and are distributed across Brazil. This study assessed the susceptibility of six pitaya genotypes (S. undatus, S. polyrhizus, S. undatus subsp. lithocarpus, S. megalanthus, S. setaceus, and S. megalanthus × S. costaricensis 'Orange') to Meloidogyne incognita and M. javanica. The experiment was conducted in a completely randomized design with 20 replicates. The total numbers of eggs and second-stage juveniles (J2), as well as eggs and J2 per gram of root, were used to calculate the reproduction factor and reproduction index. Plant assessments included measurements of shoot and root fresh weights. The pitaya genotypes S. undatus, S. polyrhizus, S. undatus subsp. lithocarpus, S. megalanthus, S. setaceus, and S. megalanthus × S. costaricensis 'Orange' were classified as susceptible to M. incognita and M. javanica, as their reproduction factors exceeded 1. Further studies are necessary to identify pitaya genotypes resistant to plant-parasitic nematodes, as genetic resistance remains one of the most effective and cost-efficient strategies for nematode control in agricultural systems.