HELIANTHUS PETIOLARIS IN ARGENTINA AND ITS SPONTANEOUS HYBRIDIZATION WITH CULTIVATED SUNFLOWER

MÓNICA POVERENE; ALICIA CARRERA; MIGUEL CANTAMUTTO; SOLEDAD URETA; CARLA DELUCCHI; VIRGINIA ALONSO ROLDÁN; JESSICA BASUALDO

Fargo

Conferencia; 16th Internacional Sunflower Conference; 2004

Helianthus petiolaris has been naturalized in central Argentina and its geographical distribution overlaps the sunflower crop region. Intermediate forms between both species are often found in wild populations. To study variability and occurrence of natural hybrids, 26 representative populations growing up to 100 m away from the sunflower crop in three provinces were sampled and a common garden experiment was conducted. Highly significant differences were found among populations for morphological quantitative traits, and there was also variation for qualitative traits and phenology. Hybrid origin of intermediate plants found in 10 out of 26 populations was assessed through morphology, phenology and fertility. Hybrid plants were rather different and all were at least partially fertile. These results have biological implications concerning gene flow and introgression, and practical ones regarding the possibility of releasing genetically modified sunflower cultivars.