Direct Regeneration of Sunflower (Helianthus annuus hyb. Farrokh) from Synthetic Seeds in Response to Different Periods of Cold Storage

In this study investigated the regrowth of sunflower plantlet shoot tips. Shoot tips of sunflower (Helianthus annuus hyb. Farrokh) were encapsulated in 3% sodium alginate to evaluate their response to different storage periods. The encapsulated shoot tips stored for several period (15, 30, 45 and 60 days) at 4°C. The regrowth ability of encapsulated shoot tips was affected by the storage duration and the presence or absence of MS nutrients and plant growth regulator in calcium alginate beads. Maximum percent germination of artificial seeds in non-encapsulated shoot tips and encapsulated in DDW, MS, MS+ growth regulator was 30, 40, 65 and 70 respectively. that obtained from synthetic seeds cultured on MS medium without plant growth regulators stored for 60 days. The longer duration of cold storage, caused the less in plantlet recovery. It can be said that encapsulated plantlets could be regenerated for a limited period under in vitro condition. Addition of MS nutrients in calcium alginate beads significantly improved encapsulated explants regrowth after storage periods