Altın çilekte (physalis peruviana l.) in vitro rejenerasyon protokolü geliştirilmesi, sentetik tohum üretimi ve antioksidan aktivitesinin belirlenmesi

Physalis peruviana L., commonly known as goldenberry or cape gooseberry contains polyphenols and carotenoids with anti-inflammatory and antioxidant activities used against diabetes. A highly efficient in vitro culture protocol of this plant was developed via direct and indirect organogenesis. To establish a rapid regeneration system, nodal explants excised from 4-week-old germinated seedlings were cultured on different plant growth regulators (KIN, BAP, Zeatin, TDZ, GA3, IAA, IBA, NAA) at various concentrations (0.1, 0.5, 1.0 or 2.0 mg/l) and combinations. The highest mean number of shoots was obtained on MS medium containing 0.5 mg/l TDZ, producing 6.5 shoots per explant with 100% explants developing shoots within four weeks of incubation. The highest root formation was achieved on MS containing 2.0 mg/l IAA, producing 9.0 roots per explant, with 100% rooting responses. Due to the high regeneration capacity of nodal segments, synthetic seed was developed using sodium alginate (NaAlg) encapsulation techniques. Four different matrix compositions, including NaAlg, NaAlg together with MS medium with or without 3% (w/v) sucrose or in combination with 0.5 mg/l abscisic acid (ABA) as a growth retardant, were tested for the regrowth performance of synthetic seeds after storage at +4 °C up to 70 days. Of the tested matrix compositions, the highest re-germination rate was observed from nodal segments encapsulated in NaAlg bead containing MS medium and sucrose, with 60% conversion after 70 days of storage. In addition, the effects of soil and MS as a sowing medium for synthetic seeds were also compared, and MS medium was found more productive than soil. Antioxidant activity of fruit, leaf, stem, calyx and callus extracts obtained from in vitro-derived regenerants as well as fruit, leaf, stem and calyx extracts obtained from seedlings germinated under ex vitro were also compared. Regardless of plant resource, the highest antioxidant capacity, total phenolics and flavonoids were obtained from fruit extracts followed by stem and calyx extracts. Leaf and stem extracts obtained from regenerants show more antioxidant activity than those obtained from seedlings. This study not only demonstrates the interest in alternative sources of natural antioxidants but also provides a new insight into protocol development for micropropagation and synthetic seed production of many solanaceous species with economic relevance.