Impact of 2,4-D and potato (Solanum tuberosum L.) tuber age on anthocyanin content of skin and phellem anatomy of Red Norland

Authors: Busse, James; Bethke, Paul

Submitted to: American Journal of Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/29/2019
Publication Date: 12/20/2019
Citation: Busse, J.S., Bethke, P.C. 2019. Impact of 2,4-D and potato (Solanum tuberosum L.) tuber age on anthocyanin content of skin and phellem anatomy of Red Norland. American Journal of Potato Research. 97:102-110(2020). https://doi.org/10.1007/s12230-019-09760-5.
DOI: https://doi.org/10.1007/s12230-019-09760-5

Interpretive Summary: Attractive appearance is a highly desirable characteristic of red-skinned potatoes. Some growers seek to intensify red skin color by treating vines with the synthetic plant growth regulator 2,4-D. In this study we examined the effects of 2,4-D treatment on tuber growth rate and skin color of Red Norland potatoes. 2,4-D treatment decreased average tuber size at plant maturity and increased the amount of red pigment in the skin throughout the growing season. Changes in pigmentation were not mirrored by changes in the number of pigmented skin cells or the thickness of the potato skin. Overall, the findings suggest that changes in pigmentation are initiated rapidly by application of 2,4-D early in the growing season and persist for months in storage. This information can be used by potato growers who are looking for ways to enhance the value of the crop and researchers who want to understand better how 2,4-D affects potato tuber growth and quality.

Technical Abstract: Attractive appearance is a highly desirable characteristic of red-skinned potatoes. Red potatoes derive their skin color from anthocyanin pigments. Some growers manage red skin color by treating vines with the synthetic auxin 2,4-D. In this study, 2,4-D was applied twice at early bloom stage to ‘Red Norland’ potatoes and tubers were harvested weekly until plants senesced. 2,4-D rapidly increased anthocyanin quantity and altered anthocyanin composition. Average tuber size at the final harvest was less for the 2,4-D-treatment than untreated controls . Elevated anthocyanin content resulting from 2,4-D persisted through 3 months storage. 2,4-D-treated potatoes did not differ from untreated controls in the number of red pigmented cells and the thickness of the phelloderm. Thus, changes in periderm cell division and expansion may not contribute to the 2,4-D response of ‘Red Norland’. Instead, the data suggest that changes in anthocyanin accumulation are initiated rapidly by 2,4-D and persist into storage.