Development of drought tolerant breeding lines derived from Helianthus annuus × H. argophyllus interspecific crosses (Plant Breeding)

Due to climate change, drought stress is threatening sunflower yield, and phenotypic diversity could be the solution. Here Hussain et al. studied the introgression of silver canopy traits related to lower excised leaf water loss (high cuticular waxes, intense hairiness, and smaller leaf area) from the wild species known as “silver sunflower” (Helianthus argophyllus) into sunflower elite lines to produce drought tolerant lines. Interspecific derived F₆ lines (IDL) were obtained by crossing emasculated H. annuus with H. argophyllus pollen and self pollination after F₁. Drought related and agronomic traits (head diameter, oil content, seed setting and pollen fertility) were selected in segregating generations. F₆ lines showed 22% lower excise leaf water loss and 141% higher cuticular waxes as analyzed via gas chromatography. However, IDL were later and asynchronously flowering, which showed positive significant correlation with higher cuticle wax. The authors analyzed General Combining Ability (GCA), breeding value under stress and non stress conditions and heritability estimates in promising IDL. Lines with positive GCA values may be useful as breeding parents or in heterosis breeding. (Summary by Ana Valladares). Plant Breeding. 10.1111/pbr.12731.