Developing drought and broomrape resistant sunflower germplasm utilizing wild Helianthus species

Abstract

In this paper we present the results of the study of new sunflower forms obtained through hybridization between cultivated sunflower (Helianthus annuus) and two wild Helianthus species. Wild species H. argophyllus and H. maximiliani were used in order to improve drought and broomrape resistance of some Romanian sunflower inbreed lines. The investigation encompassed the period 2008-2009. Interspecific F1 plants were obtained by embryo rescue techniques, and BC2, F3 were obtained as a result of self-pollination and backcrossing with cultivated sunflower. The heritability in the first generation was intermediate, but the plants strongly resembled the wild species in most biomorphological traits. The plant with pubescent leaves was selected for drought resistance. The F2 plants were also investigated for broomrape resistance using tests performed under artificial inoculation with broomrape seeds from two infested areas in Romania. Concerning drought and broomrape resistance the results indicated good resistance, suggesting successful gene introgression. Resistant lines will be self-pollinated and retested in the next year and some of the obtained hybrid forms will be included in the sunflower breeding program as genetic sources for drought and broomrape resistance.