Modified light spectral conditions prior to cryopreservation alter growth characteristics and cryopreservation success of potato (Solanum tuberosum L.) shoot tips in vitro

Abstract

Light is one of the most important factors affecting growth and morphogenesis of plants. Light intensity, photoperiod and spectral composition greatly affect morphogenetic responses of in vitro plants. Modification of light spectra during recovery after cryopreservation improves survival and regeneration, but the effect of modified light conditions prior to cryopreservation are not known. Therefore, the aim of the present study was to follow the photomorphogenetic response of potato plants (Solanum tuberosum L.) under different light qualities i.e. cool white fluorescent (CW) used as control, warm white (HQI), white LEDs (W), blue LEDs (B), red LEDs (R) and a combination of red with 10 % of blue LEDs (RB) prior to cryopreservation, affecting recovery of cultivars Agrie Dzeltenie, Bintje, Maret, Anti and Desiree in vitro. Light spectral quality had a significant effect on growth characteristics of potato plants in vitro. Red light (R) promoted elongation growth but biomass accumulation remained low under monochromatic light treatments. Some of the pre-cryopreservation light treatments significantly affected post-cryopreservation success. Under blue LEDs, high early recovery was observed for all cultivars tested, whereas under red (R) or (HQI), lowest survival percentages were obtained 2–4 weeks after thawing. Specifically, during early recovery, blue light increased survival from 26 to 66 %, 4 to 31 % and 16 to 48 % for cultivars Agrie Dzeltenie, Anti, and Desiree, compared to illumination by red LEDs. Therefore, light spectral quality prior to cryopreservation can significantly affect the cryopreservation success of potato shoot tips.