Tolerance of 26 native tomato collections from Mexico to nematode Meloidogyne incognita (Kofoid and White) Chitwood [Tolerancia de 26 colectas de tomates nativos de México al nematodo Meloidogyne incognita (Kofoid y White) Chitwood]

The tolerance of 26 native tomato collections from Mexico to Meloidogyne incongnita (Kofoid and White) Chitwood was studied to identify those with potential for use in breeding or as rootstock. To do this, 30-day-old plants were established in a hydroponic system under greenhouse conditions. A solution with 100,000 eggs-larvae per plant was applied to the substrate 10 days after transplantation (dat). Characters of the above-ground part of the plants were recorded and at 210 dat the development of nematode populations in roots was quantified. Meloidogyne incognita reduced fruit diameter and plant size (first truss height, stem dry weight, and node number), and increased the number of fruits and flowers. Additionally, it reduced root length and increased root volume due to nodule formation. By means of multivariate analysis (cluster and discriminant), five collection groups were defined based on the number of small and large galls, as well as total galls (82 % variation), and by the number of larvae in roots and eggs in the substrate (13 % variation). Three tolerant collections with low gall indices and a lower number of eggs-larvae in the roots and substrate were identified. Eight collections were moderately tolerant, nine moderately susceptible and six susceptible. No associations were detected between collection origins or fruit shape and tolerance to nematode