Tomato is one of the most important vegetable crops in northwest Mexico. In Sinaloa, Mexico, in the horticultural cycle 2012-2013, 13 785 hectares were planted, of which 2 405 were for protected areas (shade and greenhouse mesh).

During the last ten horticultural cycles, there has been the presence of root galls on different commercial tomato hybrids. However, in the 2012-2013 cycle was observed in shade mesh conditions, damage of the nematode galls in the indeterminate hybrid tomato cv Ramsés, which report it with high resistance to damage of the species Meloidogyne incognita, M. javanica and M. arenaria.

The symptoms caused by nematode damage include stunting of the plants, the presence of root galls resulting reduction in yield. This indicates that, the damage to these plants could be caused by a nematode species not yet detected in the study area, therefore, the objective of this research was to identify the root-knot nematode species responsible for the disease.

We collected 20 sub samples of soil and roots galled in tomato cv Ramses under shade in the valley of Culiacan, which is homogenized to form a single sample (2 kg). The extraction of males and juveniles was performed by screen-funnel technique (^{Cobb, 1918}). To remove adult females from the roots, we used the crushed-tissue technique and proceeded to identification, genus and species level. Globose females specimens were dissected, for perineal patterns or models. Each of the patterns or models presented perineal females as compared with those reported by ^{Yang and Eisenback (1983)}.

For confirmation though molecular techniques of the identity of Meloidogyne, 50 females were extracted with a dissecting needle and placed in a microcentrifuge tube 1.5 mL; subsequently, an aliquot of 45 mL of lysis buffer (NaOH 50mM) was lysed by heating at 95 °C for 10 min, an aliquot of 45 mL of Tris-HCl (pH 8) was added and centrifuged for 3 min at 10 000 rpm (^{Hu et al., 2011}); the supernatant was recovered, to proceed with PCR using specific primers pair of Me-F (5'-AACTTTTGTGAAAGTGCCGCTG-3') and Me-R (5'-TCAGTTCAGGCAGGATCAACC-3'), encoding a portion of the region rDNA-IGS2 (^{Long et al., 2006}).

PCR reactions were performed using the PCR Core Systems system 1 (Promega). The total volume of the reaction mixture was 25 uL for all reactions. The content of the reaction mixture was: 10 ng of genomic DNA, 5 uL of 10 x PCR buffer, 3 uL of MgCl2 (25 mM), 0.5 l of each dNTP (10 mM), 1 uL of each primer, 0.2 uL Taq polymerase (5u/microL) and the rest of sterile nanopure water. DNA amplification was performed in a thermocycler (BIO-RAD T100) under the following amplification conditions: 94 °C for 2 min, 35 cycles of 94 °C for 30 s, 64 °C for 30 s, 68 °C for 1 min, followed by a final extension at 72 °C for 5 min.

An aliquot of the PCR product was visualized in a gel of 1% agarose, stained with 1 ml of ethidium bromide (10 mg mL^-1), transillumination (Benchtop UV). The positive response was defined as a visible band of 256 bp. Additionally, the population density of Meloidogyne in the collected soil was evaluated and a test was performed to confirm the pathogenicity of nematodes on cv Ramses.

The pathogenicity test was performed in 30 tomato seedlings cv Ramsés 4 weeks old, grown in pots containing 5 kg of substrate formed of soil (sterile) and coir in 3: 1 ratio, which was applied one inoculum dose of 15 larvae per 100 g soil. In control plants, only distilled water was added. The plants were kept in a greenhouse at 28 °C and 70% RH, watered when necessary and a dose of fertilizer was applied (10 meq L^-1 NO₃, 1.5 meq L^-1 H₂PO₄, 3 meq L^-1 of SO₄, 8 meq L^-1 of K, 6 meq L^-1 of Ca and 5 meq L^-1 of Mg) at the start of the experiment.

The nematode population in the sample collected fluctuated between 300 and 315 larvae per 100 g of soil. The juveniles (J2) were characterized as vermiform ringed with tapered ends, 406.3-469.9 microns long. The males are vermiform, ringed forward and slightly rounded back, resizable, where the stylus ranged between 21.3 and 24.9 microns. Females are ringed with white lateral fields and piriform shape, resizable. The relationship between the distances from head to excretory pore ranged from 4.1 to 4.5 µm, settling at metacorpus level. The length of the stylet was 13.0-17.8 microns. Perineal patterns were ovoid to rounded with rounded moderately high arc. The morphological and morphometric characteristics are similar to those reported by EPPO in 2011 to M. enterolobii (^{Yang and Eisenback, 1983}) or its synonym M. mayaguensis (^{Rammah and Hirschmann, 1988}).

In pathogenicity tests, galling and nematode injury symptoms was observed at 45 days after inoculation. Nematode extraction was performed, and the morphological identification by PCR was performed in female nematode taken directly from the formed galls confirmed, thus, confirming the pathogenicity of M. enterolobii . In control plants no damage was observed by nematode. The experiment was repeated under the same conditions and similar results were obtained.

Although, M. enterolobii has been detected in several countries including Congo, Ivory Coast, Malawi, Senegal, South Africa, USA, Brazil, Costa Rica, Cuba, Guatemala, Martinique, Trinidad and Tobago, Venezuela and France, and in crops like: Capsicum annuum L., Citrullus lanatus L., Coffea arabica L., Glycine max L., Ipomoea batatas L., Solanum lycopersici L., Nicotiana tabacum L., Phaseolus vulgaris L., Psidium vulgaris L., Psidium guajava L., Solanum melongena L. and ornamental plants, in Mexico there is only reports by ^{Ramirez et al. (2014)} who identified M. enterolobii causing damage on watermelon cultivated in the State of Veracruz.