Clonal propagation and synthetic seed production from nodal segments of Cape gooseberry (Physalis peruviana L.), a tropical fruit plant

摘要

Physalis peruviana L. contains polyphenols and carotenoids with antiinflammatory and antioxidant activities used against diabetes. To establish an efficient regeneration system using nodal segments excised from 4-week-old germinated seedlings, direct plant regeneration, without additional rooting stage, was achieved on LS medium containing 0.5 mg/L 6-benzylaminopurine (BAP), kinetin (KIN), thidiazuron (TDZ), or gibberellic acid (GA(3)), alone or in combination with 0.25 mg/L indole-3-acetic acid (IAA) or indole-3-butyric acid (IBA), after 2 weeks of incubation. The highest mean numbers of shoots and well-developed roots were obtained on LS medium containing solely 0.5 mg/L TDZ, producing 5.3 shoots and 3.3 roots per explant after 2 weeks of incubation. Direct shoot and root formation were also recorded on LS medium containing no plant growth regulators. Due to the high regeneration capacity of nodal segments, synthetic seed production was also investigated using the sodium alginate (NaAlg) encapsulation technique. Four different matrix compositions, including NaAlg with or without LS medium containing 3% (w/v) sucrose alone 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 degrees C up to 70 days. The highest regrowth (100%) was observed at 28 days of storage for all matrix compositions. All plantlets were acclimatized to the soil and then progressively transferred to the field. The fruits were harvested after 5 months. This study might provide a new insight through protocol development for micropropagation and synthetic seed production of many solanaceous species with economical relevance.