Axis 2: Oomycetes


Oomycetes quickly overcome deployed plant genetic resistances, usually conferred by major resistance genes. Polygenic resistance with lower selective pressure and combining different geographical origins could slow down or hamper the pathogen’s ability to adapt to these combinations.

We identify and characterize plant quantitative factors in plants (tomato and pepper) and identify the aggressiveness factors in two of their oomycetes pathogens (Phytophthora infestans and P. capsici, respectively):

  • by exploring the natural diversity of vegetable crops and wild related species
  • by exploring the diversity within pathogens from cultivated and non-cultivated geographical areas
  • by studying the interactions between plant and oomycetes and deciphering partial resistance at the molecular level
  • by assessing robustness of these resistance to environmental changes (abiotic and biotic)
  • by developing new genotypes combining polygenic resistance alleles and challenging their efficiency to oomycetes

Relevant Publications

Caromel B, Hamers C, Touhami N, Renaudineau A, Bachellez A, Massire A, Damidaux R, Lefebvre V (2015). Screening tomato germplasm for resistance to late blight.  INNOHORT, Innovation in Integrated & Organic Horticulture. ISHS International Symposium, Avignon (France), 8-12 June 2015, pp 15-16

Mallard et al. (2013). A key QTL cluster is conserved among accessions and exhibits broad-spectrum resistance to Phytophthora capsici: a valuable locus for pepper breeding. Mol Breeding 32(2):349-364

Nicolaï et al. (2013). Genotyping a large collection of pepper (Capsicum spp.) with SSR loci brings new evidence for the wild origin of cultivated C. annuum and the structuring of genetic diversity by human selection of cultivar types. Genet Resour Crop Ev 60:2375-2390

Thabuis et al. (2003). Comparative mapping of Phytophthora resistance loci in pepper germplasm: evidence for conserved resistance loci across Solanaceae and for a large genetic diversity. Theor Appl Genet 106(8):1473-1485


Véronique Lefebvre (vé

Emmanuel Szadkowski (

Modification date : 21 June 2023 | Publication date : 24 February 2022 | Redactor : C Lebaron