Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 7, 1997
Publication Date: N/A
Interpretive Summary: Cultivated sunflower ranks second only to soybean among field crops grown for the production of edible oil. It is also the second largest hybrid crop in the world. Unfortunately, it is based on a single male sterile cytoplasm as the female parent with a limited number of male pollinators. Wild sunflowers are the ancestors of the cultivated sunflower. The ancestors comprise a strong natural variation for morphological and physiological characteristics. The problem is that many of the species are very distant relatives of the cultivated sunflower so the breeding of the wild relative with cultivated sunflower can be very difficult. In the present study we have developed interspecific germplasm lines to add diversity to the cultivated sunflower. The lines are rather primitive and are based on three annual species and one perennial species. Based on the present breeding system in sunflower, these lines offer the opportunity to introduce foreign genes directly into the cultivated sunflower. Utilization of these germplasm lines in a sunflower breeding program has the potential of increasing the genetic diversity for disease resistance and decreasing the genetic vulnerability of cultivated sunflower.
Technical Abstract: Wild sunflower species possess considerable variability for most economic and agronomic characteristics, especially disease and insect resistance. The present breeding system in sunflower is based on the cytoplasm male sterility (CMS) system with complementary restoration genes. Since we presently use only one cytoplasm, (PET1) as the female parent, the way to increase genetic diversity is to introduce genes into the male side of the system. Ten interspecific restoration lines for the PET1 cytoplasm have been developed. They are based on three annual and one perennial species. All lines possess dominant fertility restoration genes for the PET1 cytoplasm at high frequencies varying from 57 to 100%. Nine of the lines possessed single dominant genes for fertility restoration, and one with restoration controlled by three genes. The lines exhibit an annual habit and are mostly single-headed. The germplasm lines flower about the same time as a commercial hybrid, but have lower self-compatibility, oil content, seedweight, and test weight. Incorporation of restoration genes from the released lines have the potential to increase the genetic diversity in cultivated sunflower.