Comparative mapping of Phytophthora resistance loci in pepper germplasm: evidence for conserved resistance loci across solanaceae and for a large genetic diversity

• Published in: Theoretical and applied genetics Vol. 106; no. 8; pp. 1473 - 1485
• Main Authors: THABUIS, A, PALLOIX, A, PFLIEGER, S, DAUBEZE, A.-M, CARANTA, C, LEFEBVRE, V
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.05.2003; Berlin Springer Nature B.V; Springer Verlag
• Subjects: Biological and medical sciences; Capsicum - genetics; Capsicum - microbiology; Cell physiology; Fundamental and applied biological sciences. Psychology; Genes, Plant; Genetic Variation; Genetics; Life Sciences; Molecular and cellular biology; Phenotype; Phytophthora - pathogenicity; Quantitative Trait Loci; Signal transduction; Solanaceae - genetics; Genetic mapping; Phytophthora capsici Leonian; Phycomycetes; QTL; Genetic diversity; Epistasis; Fungi; Resistance; Capsicum annuum L. Disease resistance; Germplasm; Dicotyledones; Angiospermae; Spermatophyta; Phytophthora; Solanaceae; Thallophyta; RELATION HOTE PATHOGENE
• ISSN: 0040-5752; 1432-2242
• DOI: 10.1007/s00122-003-1206-3

Phytophthora capsici Leonian, known as the causal agent of the stem, collar and root rot, is one of the most serious problems limiting the pepper crop in many areas in the world. Genetic resistance to the parasite displays complex inheritance. Quantitative trait locus (QTL) analysis was performed in three intraspecific pepper populations, each involving an unrelated resistant accession. Resistance was evaluated by artificial inoculations of roots and stems, allowing the measurement of four components involved in different steps of the plant-pathogen interaction. The three genetic maps were aligned using common markers, which enabled the detection of QTLs involved in each resistance component and the comparison of resistance factors existing among the three resistant accessions. The major resistance factor was found to be common to the three populations. Another resistance factor was found conserved between two populations, the others being specific to a single cross. This comparison across intraspecific germplasm revealed a large variability for quantitative resistance loci to P. capsici. It also provided insights both into the allelic relationships between QTLs across pepper germplasm and for the comparative mapping of resistance factors across the Solanaceae.