A high throughput method for generating dihaploids from tetraploid potato

Authors: Busse, James; Jansky, Shelley; AGHA, HUSAIN - University Of Minnesota; SCHMITZ CARLEY, CARI - Jr Simplot Company; SHANNON, LAURA - University Of Minnesota; Bethke, Paul

Submitted to: American Journal of Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/21/2021
Publication Date: 8/17/2021
Citation: Busse, J.S., Jansky, S.H., Agha, H., Schmitz Carley, C.A., Shannon, L.M., Bethke, P.C. 2021. A high throughput method for generating dihaploids from tetraploid potato. American Journal of Potato Research. 98:304–314. https://doi.org/10.1007/s12230-021-09844-1.
DOI: https://doi.org/10.1007/s12230-021-09844-1

Interpretive Summary: Potato variety improvement is a slow process, in part because potatoes have four copies of each chromosome; they are tetraploid. There is a worldwide effort to increase the efficiency of variety development through the creation of inbred diploid potato breeding lines with two copies of each chromosome. This activity is impeded by the time and effort required to produce dihaploid individuals from cultivated tetraploid potatoes. One way to overcome these challenges is to increase the scale of dihaploid production while maintaining cost efficiency. We developed a large scale, high throughput dihaploid production method. Potato shoots bearing unopened flower buds were collected from commercial fields, brought indoors and placed in water. As buds developed, pollen from a variety that produces dihaploids at a very low rate was applied systematically to thousands of flowers. Seed was collected and putative dihaploids were retained. We recovered over a dozen dihaploids from more than eight thousand pollinations. This is a promising, low-cost method because each step is carried out rapidly and systematically on thousands of flowers. By using flowers grown in production fields, the cost per flower was dramatically reduced relative to the cost of greenhouse-grown plants. This research will benefit potato breeders who are producing and using dihaploid potatoes. This research contributes to the larger effort to make potato a diploid crop. The needs of consumers and industry can be met more rapidly through conventional breeding using diploid rather than tetraploid potatoes.

Technical Abstract: otato variety improvement is a slow process, in part because potatoes have four copies of each chromosome; they are tetraploid. There is a worldwide effort to increase the efficiency of variety development through the creation of inbred diploid potato breeding lines with two copies of each chromosome. This activity is impeded by the time and effort required to produce dihaploid individuals from cultivated tetraploid potatoes. One way to overcome these challenges is to increase the scale of dihaploid production while maintaining cost efficiency. We developed a large scale, high throughput dihaploid production method. Potato shoots bearing unopened flower buds were collected from commercial fields, brought indoors and placed in water. As buds developed, pollen from a variety that produces dihaploids at a very low rate was applied systematically to thousands of flowers. Seed was collected and putative dihaploids were retained. We recovered over a dozen dihaploids from more than eight thousand pollinations. This is a promising, low-cost method because each step is carried out rapidly and systematically on thousands of flowers. By using flowers grown in production fields, the cost per flower was dramatically reduced relative to the cost of greenhouse-grown plants. This research will benefit potato breeders who are producing and using dihaploid potatoes. This research contributes to the larger effort to make potato a diploid crop. The needs of consumers and industry can be met more rapidly through conventional breeding using diploid rather than tetraploid potatoes.