Molecular Marker Assisted Selection in Breeding for Resistance to Bacterial Wilt in Carnation (Dianthus caryophyllus L.)

Abstract

The availability of marker-assisted selection (MAS) using DNA markers close to QTLs of resistance to bacterial wilt in carnations (Dianthus caryophyllus L.) was examined. The STS-WG44 marker tightly linked to the major resistant gene was detected in all backcross lines with resistance selected by the root-soaking method. Quantities of markers OQ12 and STS-WB66 close to QTLs with slight effects in resistant lines were lower in succeeding generations of backcrossing. These findings suggested that STS-WG44 is available for selecting resistant lines. In practical breeding populations, the difference of mean disease incidence between two groups categorized as having or lacking STS-WG44 was 62.6% and STS-WG44 was possessed in most lines showing resistance less than 20% in disease incidence. These findings suggest that STS-WG44 as a selective marker facilitated narrowing of populations to those that are highly resistant for practical breeding. Marker-assisted selection would be available for breeding improved resistance to bacterial wilt in carnations.