Screening of Wild Helianthus Species and Derived Lines for Resistance to Several Populations of Orobanche cernua . J. Ruso, Former Graduate Students, Departamento de Mejora y Agronomfa, Instituto de Agricultura Sostenible, CSIC. J. Dominguez-Gimenez, Research Breeder, Departamento de Mejora y Agronomfa, CIDA de Cordoba, Apdo. 4240, 14080, Cordoba, Spain;J. M. Melero-Vara, Research Pathologist, Departamento de Proteccion Vegetal; and J. Fernandez-Martinez, Professor, Departamento de Mejora y Agronomfa, Instituto de Agricultura Sostenible, CSIC, Apdo.4084, 14080, Cordoba, Spain. Plant Dis. 80:1165-1169. Accepted for publication 2 July 1996. Copyright 1996 Tha American Phytopathological Society. DOI: 10.1094/PD-80-1165.

Twenty-six different perennial species of Helianthus, 18 wild annual species of the same genus, and 29 lines tracing to wild species were evaluated for resistance to three highly virulent populations of broomrape (Orobanche cernua). Evaluations were carried out in pots containing soil mixture infested with broomrape seeds. Most of the perennial Helianthus species were immune to the populations of broomrape used in the tests. Some wild annual species and wild derived lines were resistant. The resistance found in the wild species, introgressed to cultivated sunflower, could provide unique resistance to the parasite.