36th International Carrot Conference Abstract

Inheritance and mapping of Mj-2, a new source of root-knot nematode (Meloidogyne javanica) resistance in carrot

Aamir Ali^1,2, W.C. Matthews³, Pablo F. Cavagnaro^2,4, Massimo Iorizzo², Philip A. Roberts³, and Philipp W. Simon^2,5,* From the ¹Department of Biological Sciences, University of Sargodha, Sargodha, Pakistan; ²Department of Horticulture, Plant Breeding and Plant Genetics Program, University of Wisconsin-Madison,1575 Linden Drive, Madison, WI 53706; ³Department of Nematology, University of California, Riverside, CA 92521; ⁴CONICET, Facultad de Ciencias Agrarias – Universidad Nacional de Cuyo and INTA-EEA La Consulta, CC8 La Consulta (5567), Mendoza, Argentina; and the ⁵U.S. Department of Agriculture – Agricultural Research Service, Vegetable Crops Unit, Dept. of Horticulture, University of Wisconsin-Madison,1575 Linden Drive, Madison, WI 53706 Root-knot nematodes limit carrot production around the world by inducing taproot forking and galling deformities that render carrots unmarketable. In warmer climates, Meloidogyne javanica and M. incognita are most prevalent. In F₂ and F₃ progeny from the cross between an Asian carrot resistant to M. javanica, PI 652188, and a susceptible carrot, resistance response was incompletely dominant with a relatively high heritability (H² = 0.78) and evidence for a single gene, designated Mj-2, contributing to resistance. Molecular markers linked to the previously described root-knot nematode resistance gene, Mj-1 on chromosome 8 derived from ‘Brasilia’, demonstrated that Mj-2 does not map to that same locus, but is on the same chromosome.

Last updated Friday, 02-Aug-2013 11:54:21 CDT