Genetics of Agronomic Traits in Sunflower.

Cultivated sunflower (Helianthus annuus L.) is grown worldwide as an oilseed crop.  To obtain a better understanding of the genetics of agronomic traits in sunflower we developed 282 advanced-intercross recombinant inbred lines (AI-RILs) from a hybrid between NMS-RHA373 (PI560141), an elite apically-branched oilseed inbred line, and Hopi (PI369359), an unbranched Native American landrace. The Hopi landrace is a large, highly productive, monocephalic line that originates from a historic population of sunflower cultivated by the Hopi people in northern Arizona.  The AI-RIL population was grown and phenotyped in Ames, Iowa and Athens, Georgia in 2009 and 2010.  This population expressed extensive diversity for agronomic traits including days to flower, plant height, branching (number and type), leaf area, head and stem diameter, stem density, total plant biomass, seed size and shape and seed oil content.  A framework genetic map of 135 SSR markers was constructed and used for QTL mapping. We plan to genotype NMS-RHA373 x Hopi this Spring with a 10,640-SNP Infinium iSelect BeadChip to construct an ultra high-density genetic map.  The goals of this experiment are geared towards increasing seed, oil, and biomass yield and further exploring the potential of sunflower as a biomass and biofuel crop through the identification and development of very high vegetative biomass, high oil producing genetic materials.