Development of drought-tolerant breeding lines derived from Helianthus annuus × H. argophyllus interspecific crosses

Authors: HUSSAIN, MUHAMMAD - University Of Sargodha; RAUF, SAEED - University Of Sargodha; Warburton, Marilyn

Submitted to: Plant Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/31/2019
Publication Date: 7/25/2019
Citation: Hussain, M.M., Rauf, S., Warburton, M.L. 2019. Development of drought-tolerant breeding lines derived from Helianthus annuus × H. argophyllus interspecific crosses. Plant Breeding. 138(6):862-879. https://doi.org/10.1111/pbr.12731.
DOI: https://doi.org/10.1111/pbr.12731

Interpretive Summary: Genes for valuable trait for the improvement of commercial sunflowers can be found in the wild relatives of this crop. These genes can be moved from the wild species into cultivated sunflower and used to improve traits including tolerance to environmental stresses such as drought stress. Genes for this trait were found in the wild sunflower H. argophyllus, also known as “silver sunflower”, and some of these genes were transferred to cultivated sunflowers by crossing the two species and selecting offspring with the desired characteristics. However, while the resulting lines were much more drough tolerant than the cultivated sunflower parent, they tended to yield lower than desired. Thus, further breeding, possibly by crossing the best newly developed lines to high performing cultivated sunflower lines, should be considered.

Technical Abstract: Sunflower (Helianthus annuus) wild relatives have been a valuable source for genetic improvement of elite sunflower germplasm. H. argophyllus is a wild species known as “silver sunflower”, which posesses several traits, including morphological traits, that increase drought tolerance. Therefore, introgressions between chosen cultivated lines and two H. argophyllus accessions were made, and segregating generations were established. Important agronomic traits including single heading, high pollen fertility, silver canopy (indicating more cuticular wax), and content of cuticular waxes and oil were selected over 6 segregating generations. The resulting F6 lines showed introgression of water saving traits, as they had lower exicse leaf water loss, with comparable yield to standard checks. However, these F6 lines were late maturing and showed poor flowering synchronization between the cultivated and introgressed lines. Introgressed line “D-22” was particularly promising as a breeding line, with superior agronomic and drought resistance traits including high cuticular waxes, larger leaf area, intense hariness, and lower exicse leaf water loss. This line had the potential to be used as an inbred parental line for introgression of drought resistance traits into elite sunflower germplasm. Combining ability analysis of the introgressed lines further showed their potential for heterosis breeding or to be used as parental lines in breeding program.