GENETIC RESOURCES FOR IMPROVING RESISTANCE TO THE MAIN DISEASES IN SUNFLOWER

Genetic resources in sunflower, which could to be used as base of creating new inbred lines or as donor sources for genes controlling different characteristics in the inbred lines breeding, are made up of old or new varieties, hybrids and inbred lines, induced mutations, synthetic populations, as well as sunflower wild species. For improving sunflower resistance to the main diseases all these genetic resources can be used. In the sunflower breeding program of the National Agricultural Research & Development Institute (NARDI) Fundulea, Romania, we have used especially varieties, hybrids, inbred lines and sunflower wild species. The varieties and inbred lines were used for creating synthetic populations, which formed the base of obtaining new inbred lines resistant to Plasmopara halstedii (genes for resistance to different races of this pathogen). Sunflower wild species have been used for crossing with cultivated sunflower, obtaining interspecific hybrids, which allowed creating different donor sources of genes for resistance to Plasmopara halstedii, as well as to Sclerotinia sclerotiorum. We obtained some populations which are still in the breeding process for creating inbred lines with high resistance to Phoma macdonaldii and Phomopsis helianthi pathogens. We improved the resistance of some lines with good agronomic traits, to different diseases. The new inbred lines obtained by using different genetic resources were studied as general and specific combining ability for the seed yield and for oil content. Most of them were significantly superior as general combining ability for the seed yield or for oil content, or for both of them.