Increased calcium availability improves potato micropropagation and microtuberization

Summary Liquid scintillation counting (LSC) was used to screen six potato cultivars (Alpha, Bintje, Green Mountain, Kennebec, Russet Burbank, and Shepody) and two wild species(S. microdontum andS. kurtzianum) for ability to take up the tracer⁴⁵Ca²⁺ from treatment solutions containing high (15 mM) or low (5 mM) Ca²⁺ levels. In vitro potato micropropagation, microtuberization, and tissue calcium content, determined by flame atomic absorption spectrophotometry (FAAS), were compared for the six cultivars when Murashige-Skoog basal medium Ca²⁺ level was increased from 3, to 5 or 15 mM. All aspects of growth were improved when medium Ca²⁺ level was 15 mM. Microtuber induction occurred earlier, leading to improved yield (19–31%), and microtuber tissue Ca²⁺ concentration was greater (38–226%). Cv. Bintje was the most efficient genotype at accumulating Ca²⁺ from treatment solutions or growth media containing high or low Ca²⁺ levels. It could be identified as a calcium-packer using either LSC or FAAS screening.