A protocol for micropropagation of the medicinal species Tuberaria lignosa provides ploidy true-to-type plants with high antioxidant capacity

Tuberaria lignosa (Cistaceae family) has excellent properties as an antioxidant, anti-inflammatory, antimicrobial, and antiproliferative/anti-tumoural. This work aimed to establish a routine micropropagation protocol of T. lignosa to supply high-quality plants for the pharmaceutical industry. Apical shoot cuttings (0.5 cm long) were grown on basal medium Murashige and Skoog (MS) and ½MS for 60 days with different growth regulators. ½MS supplemented with 1 mg L −1 benzylaminopurine (BAP) provided the best results with shoots showing better growth rates and no vitrification or browning. After 60 days, the best results for shoot proliferation were achieved on ½MS with 1 mg L −1 mT, with 100% explants responding and ~ 4 new shoots formed per explant. For elongation and rooting, after 30 days, 1 mg L −1 indoleacetic acid (IAA) provided 100% of rooting (~ 18 roots per shoot), and resulting plants were vigorous, also with no signs of vitrification or browning. For acclimatization, the substrate Jiffy Plug provided the best results after 60 days, with a survival rate of 68.42%. In the subsequent 30 days in greenhouse conditions, all plants survived. Acclimatized plants had still less proteins, but high activity of antioxidant enzymes compared with the mother plants, supporting that these cloned plants may be of interest to the pharmaceutical industry. No changes in the DNA-ploidy were detected between micropropagated and the mother plants. The protocol described here provides, after 8 months of explant establishment, a high number of plants/explants, revealing a high potential for future use in this species and in other medicinal and economically relevant species, and in species in need of ex-situ conservation measures.