QTL MAPPING OF BROOMRAPE (OROBANCHE CUMANA WALLR.) RESISTANCE IN SUNFLOWER (HELIANTHUS ANNUUS L.) USING GBS-SNPS

Abstract

Broomrape is one of the most important biotic stresses causing serious yield reductions in sunflower. Control of this parasitic plant is difficult and physical and chemical strategies are usually insufficient. Therefore, introduction of genetic resistance to broomrape in sunflower is a key breeding goal. Breeding efforts on broomrape resistance have been conducted for decades, however, new broomrape races, such as race F, have emerged and rapidly evolved to be more aggressive and devastating. Although a few quantitative trait loci (QTLs) were identified for race F resistance, none of these loci are suitable for marker assisted selection because of their small phenotypic effects. In the present study, three major QTLs for broomrape race F resistance were identified on LG7, LG11 and LG12 using a high density SNP map constructed with the genotyping by sequencing approach in an intraspecific F2 population. The population consisted of 300 individuals derived from a cross between susceptible Helianthus annuus cv. RHA 436 as the recipient parent and resistant H. annuus cv. H08 M1 as the donor parent. Breeder-friendly SNP-based cleaved amplified polymorphic sequence markers were developed for the QTLs. The QTLs and CAPS markers identified in this study will be valuable molecular genetic tools for sunflower breeding.