A look at advances in sunflower breeding

Here is an in-depth look at the tools breeders are using today to maximize sunflower productivity and quality.

Plant scientists have been employing science to improve crops for centuries. Evidence from early cave dwellers suggests they selected seeds from plants that had the best tall stalks and seeds. A great breakthrough occurred in 1866 when Gregor Mendel, a monk and agronomist, crossed pea plants and became known as the “father of genetics.” As knowledge improved, science improved. Plant scientists (agronomists by today’s title) have advanced varieties and traits, one gene at a time.

Today, plant breeders work with several non-transgenic methods to transfer desirable traits from one plant to the next generation of plants. Sunflower is a crop that is not GMO or transgenic, which means that more traditional plant breeding techniques are employed. To use new technologies more efficiently with non-transgenic crops, plant breeders have discovered better and faster methods for transferring desirable plant traits to the next generation.

DNA marker-assisted selection (MAS) is one technology that is currently being employed. DNA markers have been found that allow a plant breeder to select specific traits more efficiently to advance to the next generation. While markers may or may not be the DNA that controls the desired trait, they act as a “flag” that points to the specific gene that plant breeders want transferred. This technology has been used since the early 2000s.

One particularly powerful form of DNA marker technology is single nucleotide polymorphism (SNP, pronounced “snip”). This plant breeding technology allows less-expensive and high-throughput DNA sequencing methods to identify and locate genes controlling important traits. SNPs located close to a particular gene act as a marker for that gene. Once the marker is identified, plant breeders know which genes to focus on and select for transfer.

Adding technology

Two other plant breeding methods that are currently getting increased attention are genomic selection and high-throughput phenotyping. Genomic selection allows the breeder to use SNPs to increase the accuracy and efficiency of trait selection, with the key goal of shortening the breeding cycle time and quickly increasing the rate of genetic gain. High-throughput phenotyping uses remote sensing and other technologies to rapidly and inexpensively evaluate breeding germplasm for drought tolerance, heat tolerance, plant biomass, pest tolerance and other important production characteristics.

Further, another new plant genetic transfer technique is called clustered regularly interspaced short palindromic repeats, or CRISPR. The CRISPR breeding method involves proteins used to change the sequence and potentially “deactivate” certain undesirable genes. For instance, CRISPR technology could disable a plant gene that allows disease or insect susceptibility, thus making the plant resistant to specific pests — without using transgenic methods. This technology could make plants more insect- or disease-resistant by turning off the bad genes and enabling the good genes to thrive, without inserting foreign genes into the plant. This could also eliminate or reduce future pesticide applications to control pests. Sunflower breeders are incorporating all these techniques to deliver the best traits possible.

As a result of improved crop production techniques, breeders are now able to reduce the time required to release a new, improved sunflower variety equipped with targeted pest-tolerant traits from 10 years to approximately three years, in some cases. Even without transgenic technology, sunflower enjoys herbicide-resistant traits found in the wild and crossed into new hybrids, giving producers advanced tools. New advances are also finding sunflower genes that are insect-resistant, which could eliminate or reduce future insecticide applications.

It is no accident that record crop yields are happening yearly. At a Colorado State University trial site near Prospect Valley, Colo., one new sunflower variety yielded 4,998 pounds per acre. Clearly, 5,000-pound-per-acre sunflower yields are reachable. While CSU does not breed new varieties, the on-farm testing team continues to explore new techniques to increase yields. To be sure, agricultural scientists are currently employing the best technology available, and the return on investment is showing up with quicker variety release times, enhanced pest resistance and higher yields, using similar inputs.