Inheritance of resistance to the peach root‐knot nematode (<i>Meloidogyne floridensis</i>) in interspecific crosses between peach (<i>Prunus persica</i>) and its wild relative (<i>Prunus kansuensis</i>)

Abstract

Abstract The peach root‐knot nematode, Meloidogyne floridensis ( MF ), infects majority of available nematode‐resistant peach rootstocks which are mostly derived from peach ( Prunus persica ) and Chinese wild peach ( P. davidiana ). Interspecific hybridization of peach with its wild relative, Kansu peach ( P. kansuensis ) , offers potential for broadening the resistance spectrum in standard peach rootstocks. We investigated the inheritance of resistance to MF in segregating populations of peach (‘Okinawa’ or ‘Flordaguard’) × P. kansuensis . A total of 379 individuals from 13 F 2 and BC 1 F 1 families were challenged with a pathogenic MF isolate “MFGnv14” and were classified as resistant (R) or susceptible (S) based on root galling intensity. Segregation analyses in F 2 progeny revealed the involvement of a major locus with a dominant or recessive allele determining resistance in progeny segregating 3R:1S and 1R:3S, respectively. Testcrosses with a homozygous‐susceptible peach genotype (‘Flordaguard’ or ‘ UFS harp’) confirmed P. kansuensis as a source of new resistance and the heterozygous allelic status of P. kansuensis at the locus conferring resistance to MF . We propose a single‐locus dominant/recessive model for the inheritance of resistance.