Submitted to: Plant Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/2/1998
Publication Date: N/A
Citation: Interpretive Summary: Sunflower broomrape is a serious parasite infecting the roots of plants that causes heavy losses to sunflower crops in many areas of the world. Adaptive evolution of this parasite to sunflower cultivars with resistance genes resulted in new virulent broomrape races. Sources of resistance were found in perennial wild species. This study reported the production of interspecific hybrids between five resistant wild perennial accessions and cultivated sunflower, the evaluation of their resistance to broomrape, and seed setting ability. The immune reaction in four of the five wild accessions and their hybrids with cultivated line indicated a simple genetic control of resistance, and the resistant plants in the progenies of the hybrids can be selected for breeding broomrape resistant lines.
Technical Abstract: Interspecific hybrids and backcross generations between wild perennial species Helianthus resinosus Small, H. pauciflorus Nutt., H. laevigatus T. & G., H. nuttallii Subsp. nuttallii T. & G. and H. giganteus L. resistant to broomrape (O. cernua Loefl.) and the susceptible inbred line 'HA89' were obtained to study the transmission and expression of resistance to this parasitic weed. F1 hybrid plants were obtained from crosses in both directions using embryo culture and conventional methods. The F1 plants of NMSHA89 x H. resinosus, NMSHA89 x H. laevigatus, NMSHA89 x H. pauciflorus, BC1F1 of the reciprocal crosses, BC1F1 of H. giganteus x HA89, and the amphiploid of H. nuttallii x P21, and its BC1F1 and BC2F1 from crosses with HA89, as well as the wild and cultivated parents, were evaluated for susceptibility to a highly virulent population of O. cernua. The wild species and interspecific hybrids were resistant to broomrape infection except for H. nuttallii which segregated for resistance. The resistance of the F1 plants and the segregation for resistance in the BC1F1 generation indicated that the resistance is dominant. The crossability and resistance of F1 and backcross generations of species with different ploidy levels indicate that the transfer of broomrape resistance to cultivated sunflower is feasible.