Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 3/8/2008
Publication Date: 6/1/2008
Citation: Marquez-Lema, A., Delavault, P., Letousey, P., Hu, J., Perez-Vich, B. 2008. Candidate gene analysis and identification of TRAP and SSR markers linked to the Or5 gene, which confers sunflower resistance to race E of broomrape (Orobanche cumana Wallr.). Proceedings of 17th International Sunflower Conference, June 8-12, 2008, Cordoba, Spain. p. 661-666.
Interpretive Summary: Six different races of sunflower, a holoparasitic angiosperm that infects sunflower roots, have been described. The inheritance of resistance of sunflower to broomrape follows the gene-for-gene model. Five resistant genes (Or1 to Or5) have been reported and used in breeding program. However, the nature of these genes conferring resistance is not known. The objectives of this study were to investigate the nature of the Or5 gene through a candidate gene approach, and to identify markers close to the gene in order to facilitate map based cloning strategies.
Technical Abstract: Sunflower broomrape (Orobanche cumana Wallr.) is a root holoparasitic angiosperm considered as being one of the major constraints for sunflower production in Mediterranean areas. Breeding for resistance has been crucial for protecting sunflowers from broomrape damage. The Or5 gene, which confers resistance to race E of broomrape, has been efficiently used for years in sunflower commercial programs to control broomrape. Despite its importance in sunflower breeding, little is known about the nature of the Or5 gene. The objective of this study was to explore different strategies to determine the nature of this gene. These include a map-based cloning strategy and a candidate gene approach.