Are the polygenic architectures of resistance to Phytophthora capsici and P. parasitica independent in pepper

Julien Bonnet (1) , Sarah Danan (1) , Christine Boudet (1) , Lorenzo Barchi (2) , Anne-Marie Sage-Palloix (1) , Bernard Caromel (1) , Alain Palloix (1) , Véronique Lefebvre (1)

1 GAFL - Génétique et Amélioration des Fruits et Légumes
2 Universita di Torino

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 architecture of resistance of CM334 to both Phytophthora species. The RIL population F5YC used to construct the high-resolution 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. Comparative mapping 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.

Mots clés: PHYTOPHTHORA CAPSICI; DISEASE RESISTANCE; GENETIC MAPPING

Mots clés: GENETIQUE VEGETALE; CARTOGRAPHIE GENETIQUE

Domaines: Génétique

Julien Bonnet, Sarah Danan, Christine Boudet, Lorenzo Barchi, Anne-Marie Sage-Palloix, et al.. Are the polygenic architectures of resistance to Phytophthora capsici and P. parasitica independent in pepper. TAG Theoretical and Applied Genetics, 2007, 115 (2), pp.253-264. ⟨10.1007/s00122-007-0561-x⟩. ⟨hal-02659540⟩