High regrowth of potato crop wild relative genotypes after cryogenic storage

Authors: Jenderek, Maria; Ambruzs, Barbara - Bobbie Ambruzs; Tanner, Justin; Bamberg, John

Submitted to: Cryobiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/18/2023
Publication Date: 3/21/2023
Citation: Jenderek, M.M., Ambruzs, B.D., Tanner, J.D., Bamberg, J.B. 2023. High regrowth of potato crop wild relative genotypes after cryogenic storage. Cryobiology. 111:84-88. https://doi.org/10.1016/j.cryobiol.2023.03.006.
DOI: https://doi.org/10.1016/j.cryobiol.2023.03.006

Interpretive Summary: Various species of wild potato were used in developing varieties grown in production fields. In the USA, the potato collection of over 5,900 samples is maintained by the USDA-ARS, Potato Genebank in Wisconsin as seeds and as tissue culture. Long-term preservation of the samples is done in liquid nitrogen (LN, called cryopreservation) at the USDA-ARS, National Laboratory for Genetic Resources Preservation in Colorado. In our study, 69 vegetative samples from 29 species were successfully placed in LN and showed viability between 40 and 100% after the LN exposure. These samples are available for improvement of varieties for farming. Wild potato (also called crop wild relatives - CWR) have several useful characteristics that support current breeding and development of cultivars for a changed weather environment; hence, preservation of the wild species is important and will contribute to potato supply in the future.

Technical Abstract: Potatoes are consumed by millions of people and provide a major source of daily caloric intake for peoples diets in several countries. Cultivated varieties of potato (Solanum tubersosum L.) are the results of selection and crossing of many wild species. Collectively only 8-13% of wild potato species used for food are preserved by either in situ or ex situ methods. The U.S. National Potato Germplasm Collection maintains over 5,900 accessions, of which 75% are crop wild relatives (CWR). The objective of the study was to investigate the viability of cryogenically stored clonal propagules (shoot tips) of selected CWR accessions maintained in the collection. Sixty-nine accessions from 29 Solanum species and six accessions that are not yet assigned to a species were cryopreserved by a droplet vitrification method at the NLGRP. The post cryopreservation viability varied from 40 to 100% (average 68%) but was not significantly different between the tested accessions; however biological variation between the accessions was observed. Survival of six accessions tested after 10 years of cryogenic storage was between 65 and 90% (average 76%) and recovery between 35 and 90% (average 66%). The recovery was significantly different from their initial viability (average 87%); the largest viability loss was in S. condolleanum; but for the other five accessions the viability was between 45-90% (average 72%) and suggested at least 10 years successful storage in LN was possible. Twelve potato wild species cryopreserved in this study were reported in literature as important for developing cultivated varieties for changed weather conditions.