Establishment of a cryopreserved genebank of potato (Solanum spp.) in New Zealand

Pathirana R1, Mathew L1, Monaghan K2, Fletcher P2, Morgan E1 and Baldwin S2

  1. The New Zealand Institute for Plant & Food Research Limited, Batchelar Road, Palmerston North 4474, New Zealand.
  2. The New Zealand Institute for Plant & Food Research Limited, 74 Gerald Street, Lincoln 7608, New Zealand.

Potato is the world’s fourth most important crop in terms of production. It has been grown in Aotearoa (New Zealand) by Maori since the 18th century. The New Zealand Institute for Plant and Food Research Ltd (PFR) has a strong potato breeding programme holding over 700 accessions. Historically, this germplasm has been maintained in the field, except for ~120 accessions maintained in tissue culture after virus elimination. Clonally propagated crops, especially annual crops like potato, require significant resources to maintain genetic material. Cryopreservation offers a robust, cost-effective solution to long-term conservation of such germplasm. In 2017 we initiated a programme to cryopreserve PFR’s collection, to reduce risk of loss due to biotic and abiotic threats. We initiate tissue cultures from tubers that have sprouted, photograph the phenotype for reference and confirm genotype identity using simple sequence repeat markers. We have adopted a modified droplet vitrification protocol for cryopreservation, which includes excision of 120 fully formed axillary buds (0.5 mm) after micropropagation, their treatment in liquid Murashige & Skoog media with 0.3 and 0.7 M sucrose over two days, followed by treatment with a plant vitrification solution (PVS2, 30 min). The explants are then mounted on aluminium foil, transferred to liquid nitrogen and 20 buds are tested for viability after one month. So far we have conserved 126 accessions, with an average viability of 79%. We will discuss our future plans for this cryopreserved collection.