In vitro Plant Regeneration of Helianthus Annuus (Hyb. Azargol) From Alginate-Encapsulated Shoot Tips for Short Term Storage, Germplasm Exchange and Distribution

The present study demonstrates the potential of nutrient-alginate encapsulation of shoot tips of sunflower, Helianthus annuus (hyb. Azargol) for synthetic seed technology, which could be useful in germplasm distribution and exchange. Shoot tips from in vitro shoot cultures derived from mature seed explants were encapsulated in 3% sodium alginate and 100 mM CaCl2. 2H2O are supplemented with three different matrices (include distilled water, liquid MS medium and plant growth regulators) and they are stored for several periods (15, 30, 45 and 60 days) at 4°C. After each storage period for regeneration and regrowth evaluation, encapsulated and non-encapsulated shoot tips were cultured on hormone-free MS medium. The regrowth ability of encapsulated shoot tips affected by the storage duration and the presence or absence of MS nutrients in calcium alginate beads. Percentage response for the conversion of encapsulated and non-encapsulated shoot tips decreased gradually after storage at 4°C by increasing storage durations. Indeed, encapsulated vegetative propagules showed a higher resistance to storage at 4°C than non-encapsulated. Addition of MS nutrients in calcium alginate beads significantly improved encapsulated explants regrowth after storage periods.