The response of Cuarentino pepper (Capsicum annuum) against 66 isolates of Meloidogyne incognita, 52 from Spain and 14 from Uruguay, was studied with the objective of evaluating its potential to be included in breeding programs as a source of resistance genes against M. incognita. A bioassay was performed to determine races and biotypes of M. incognita, as well as to characterize the resistance of Cuarentino. Cuarentino was resistant to 13.5% of the Spanish isolates (7 of 52), but was not resistant to the Uruguayan isolates of M. incognita, with no statistical differences in resistant, moderately resistant and susceptible plant frequencies among the four biotypes and races of the nematode. Proportions of biotypes were similar in both countries while the prevalence of races varied. The races of M. incognita did not affect biotype proportions. Results suggest that Cuarentino carries resistance genes to M. incognita and that these genes are different from those carried by commercial pepper cultivars. The high susceptibility of Cuarentino to Uruguayan isolates suggests that its repeated cropping in the field has selected virulent nematode populations able to overcome the resistance. It shows the need for further seed selection and agronomic behavior studies of this local pepper, as well as the need to design management strategies that avoid the selection and spread of virulent nematode populations.
