Genetic mapping of a pollinator preference trait: Nectar volume in sunflower (Helianthus annuus L.)

Authors: BARSTOW, ASHLEY - North Dakota State University; Prasifka, Jarrad; ATTIA, ZIV - University Of Colorado; KANE, NOLAN - University Of Colorado; Hulke, Brent

Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/24/2022
Publication Date: 12/19/2022
Citation: Barstow, A., Prasifka, J.R., Attia, Z., Kane, N.C., Hulke, B.S. 2022. Genetic mapping of a pollinator preference trait: Nectar volume in sunflower (Helianthus annuus L.). Frontiers in Plant Science. 13(2022). https://doi.org/10.3389/fpls.2022.1056278.
DOI: https://doi.org/10.3389/fpls.2022.1056278

Interpretive Summary: Pollinators, such as bees, find some plants more attractive than others. This is true of crop plants, such as sunflower, that are bee-pollinated, as well as bee-pollinated, non-crop plants. The purpose of this study was to find how nectar volume is inherited in sunflowers, to guide breeding of the trait in sunflower. The goal of breeding for pollinator preference traits, including nectar volume, is to enhance pollination of the crop, resulting in higher yields, while also improving the health of pollinator populations, including the honeybee. Our study found that there are two major sites on the sunflower genome that affect nectar volume in sunflower, and this information can be directly used in breeding programs to enhance pollinator use of sunflower.

Technical Abstract: Although maximizing pollinator visitation is crucial to ensure the yield output of high yielding crops, the quantitative trait loci (QTL) controlling nectar volume in sunflower (Helianthus annuus L.), a pollinator preference trait, have yet to be identified. To address this, a recombinant inbred line mapping population, derived from lines with contrasting nectar volume, was used to identify loci responsible for the phenotype. As a result, the linkage mapping and QTL analysis discovered major loci on chromosomes 2 and 16 that are associated with variation in nectar volume in sunflower. Increased nectar volume is also associated with increased sugars and total energy available per floret. The regions on chromosomes 2 and 16 associated with nectar phenotypes exhibit indications of chromosome structural variation, suggesting that these phenotypes are adaptively important for the species. These results have implications for sunflower breeding, to enhance pollination efficiency in sunflower, as well as current and future studies on sunflower evolution.