Full Text                                                                            Full-Text Online        Are the polygenic architectures of resistance to Phytophthora capsici and P. parasitica independent in pepper? Bonnet. J      Danan. S      Boudet. C      Barchi. L      Sage-Palloix. A. M      Caromel. B      Palloix. A      Lefebvre. V       Theory of Applied Genetics ;  2007  [Vol.115]  Pages:253-264 Abstract The pepper accession Criollo de Morelos 334 is the most efficient source of resistance currently known to Phytophthora capsici and P. parasitica. To investigate whether genetic controls of resistance to two Phytophthora species are independent, we compared the genetic archi- tecture of resistance of CM334 to both Phytophthora species. The RIL population F5YC used to construct the highresolution genetic linkage map of pepper was assessed for resistance to one isolate of each Phytophthora species.Inheritance of the P. capsici and P. parasitica resistance was polygenic. Twelve additive QTLs involved in the P. capsici resistance and 14 additive QTLs involved in the P. parasitica resistance were detected. The QTLs identified in this progeny were specific to these Phytophthora species. Comparativemapping analysis with literature data identified three colocations between resistance QTLs to P. parasitica and P. capsici in pepper. Whereas this result suggests presence of common resistance factors to the two Phytophthora species in pepper, which possibly derive from common ancestral genes, calculation of the colocation probability indicates that these colocations could occur by chance. Keywords phytophthora capsici p. parasitica