Production of Solanum tuberosum L. Microtuber Using Temporary Immersion System

Background: Potato (Solanum tuberosum L.) is an annual crop which belongs to the Solanaceae family of flowering plants and is native to South America. Potato is the fourth most important food crop worldwide, planted on 20 million ha globally in 2005. The need for a sustainable potato production depends on a constantly renewed supply of disease free planting material. Tissue culture micropropagation was used to revolutionize the potato industry in the 1970’s and with this technique disease-free plantlets were used to produce healthy seed tubers for farmers. This study compared the yield and nutrient profile of Spunta 58 70 77 minitubers produced by TIS with Shepody minitubers grown by local farmers. Methodology: In vitro tissue culture plantlets received from the Scientific Research Council’s genebank were grown in a TIS containing Murashige and Skoog (MS) multiplication media for three weeks at 25 ± 2°C with 16-h photoperiod under fluorescent light with a photon flux of ~52 μmol m-2s-1. After three weeks the medium was replaced with a tuber MS induction medium for six weeks in dark conditions at 25 ± 2°C. Immediately following induction, microtubers were allowed to sprout for twelve weeks in the dark at 25 ± 2°C. Traditionally grown (TG) and TIS microtubers with at least one shoot (>1 in) were then transferred to field in a randomized complete block design. After 12 weeks the physical and nutrient profiles were determined and compared. Results and Discussion: Minitubers produced by TIS had fresh weight (19.8 ± 2.1 g), length (8.1 ± 0.5 cm) and diameter (5.3 ± 0.3 cm) that were not significantly different (p ≥ 0.05) from TG minitubers with fresh weight (38.6 ± 3.7 g), length (9.4 ± 0.5 cm) and diameter (5.8 ± 0.3 cm). Similarly, the nutrient profiles of tissue culture and traditionally grown microtubers were not significantly different (p ≥ 0.05). However there was a significantly higher iron content (6.21 ± 1.04 mg/kg) in TG minituber when compared to TIS (2.01 ± 1.1 mg/kg). Temporary immersion system may be a valuable alternative for potato microtuber production. This technique could be used to increase the local production of generation one Irish potato thereby providing high quality seed potato to meet the national demand.