Tomato Mi-1.2 gene confers resistance to Meloidogyne luci and M. ethiopica

The root knot nematode (RKN) Meloidogyne luci, recently added to the European Plant Protection Organization Alert List, represents a potential threat to the production of important solanaceous crops. RKN resistance in tomato (Solanum lycopersicum L.) is conferred by a single dominant gene. The objectives were to screen the RKN resistance Mi-1.2 gene in 27 tomato hybrids and cultivars and assess the ability of M. luci and M. ethiopica to reproduce on these accessions. Thirteen Mimi tomato genotypes, two MiMi and twelve lacking the Mi-1.2 gene (mimi) were identified. Tomato accessions Reconquista (MiMi) and Vimeiro F1, Paipai, Sahel, Agora F1, Amaral, Valoasis RZ F1 and SV1917 (Mimi) displayed a resistant reaction to both RKN species with a reproduction factor (Rf) ranging from 0.00 to 0.14. Significant differences in M. luci and M. ethiopica reproduction were detected among and within the Mi-1.2 allelic conditions, which may reflect a dosage effect of the gene as well as an influence of the plant’s genetic background, respectively. Results revealed that resistant tomato accessions carrying the resistant Mi gene have potential to be employed as an alternative to the use of nematicides aiming to control M. luci, and M. ethiopica and the most common RKN species.