1Institut National de la Recherche Agronomique, UGAFL, Unité de Génétique et d'Amélioration des Fruits et Légumes, Domaine Saint Maurice, BP 94, F-84143 Montfavet cedex, France; 2BiO3P, Unité de Biologie des Organismes et des Populations Appliquée à la Protection des Plantes, BP 35327, F-35653 Le Rheu cedex, France; 3APBV, Station d'Amélioration de la Pomme de terre et des Plantes à bulbes, Kéraiber, F-29260 Ploudaniel, France
Go to article:
Accepted 28 June 2005.
Plant resistance to nematodes is related to the ability of the host to reduce the development of nematode juveniles into females. Resistance to the potato cyst nematode (PCN) Globodera pallida, originating from the wild species Solanum sparsipilum, was dissected by a quantitative trait loci (QTL) approach. Two QTL explained 89% of the phenotypic variation. The QTL GpaVsspl on chromosome V displayedthe major effect on the cyst number (coefficient of determination [R2] = 76.6%). It restricted G. pallida development to 16.2% of juveniles, 81.5% of males, and 2.3% of females. The QTL GpaXIsspl chromosome XI displayed a lower effect on the cyst number (R2 = 12.7%). It restricted G. pallida development to 13.8% of juveniles, 35.4% of males, and 50.8% of females. Clones carrying both QTL restricted the nematode development to 58.1% juveniles, 41.1% of males, and 0.8% of females. We demonstrated that potato clones carrying both QTL showed a strong necrotic reaction in roots infected by nematodes, while no such reaction was observed in clones carrying a single QTL. This result underlines the importance to introgress together GpaVsspl and GpaXIsspl into potato cultivars, in order to reduce the density of this quarantine pest in soil and to decrease the risk of selecting overcoming G. pallida subpopulations.
The American Phytopathological Society, 2005