Response of pepper rootstocks to co-infection of Meloidogyne incognita and Phytophthora spp

Summary Phytophthora spp. ( capsici and parasitica ) and Meloidogyne incognita are major pathogens of pepper in the greenhouses of south Southern Spain. Grafting on rootstocks carrying genes for resistance to the pathogens was evaluated as an alternative to chemical disinfection of soil. Under controlled conditions, the response to co-infection of M. incognita and Phytophthora capsici or P. parasitica of 7 rootstocks resistant to Phytophthora was evaluated. Two populations of M. incognita , race 2, were collected from peppers and were used for this study; one virulent on pepper rootstock Atlante (hybrid F 1 of Serrano Criollo Morelos 334, resistant to M. incognita ), and the other avirulent. Two Phytophthora isolates were tested, one highly aggressive of P. capsici , the other less aggressive P. parasitica . The infestation with M. incognita did not increase the percentage of plants affected by P. capsici or P. parasitica . The avirulent M. incognita population did not infest any rootstocks carrying Me3 or Me1 genes. The virulent population infest lowly three rootstocks two carrying Me1 and one carrying Me3 . In the rootstocks infested by M. incognita , Phytophthora was reisolated from the root lesions, although the plant did not show any wilt or root-rot Symptoms.