Effect of high concentration of thidiazuron (TDZ) combined with 1H-indole-3-butanoic acid (IBA) on Albion strawberry (<i>Fragaria × ananassa</i>) cultivar plantlets induction

Abstract

This study was conducted to understand the effects of high concentration of thidiazuron (TDZ) combined with 1H-indole-3-butanoic acid (IBA) on production of strawberry plantlets. Young folded leaves of “Albion”, “Seolhyang” and “Akihime” cultivars were collected, dipped in a detergent solution and then sterilized by treating with 70% (v/v) ethanol. The leaves were cut into 2 to 3 mm diameter pieces. Different concentrations of TDZ combined with IBA were supplemented in Murashige and Skoog (MS) medium to induce direct organogenesis. Plantlet regeneration from leaf explants was detectable at 3 weeks after culture. Plantlet regeneration rate of “Albion” was more than 60% but was very poor for ‘Akihime’ and ‘Soulhyang’ cultivars. The effect of TDZ and IBA concentrations and their interactions were significant for plantlet regeneration rate and plantlet number per explant. Plantlet regeneration rate increased with increment of TDZ concentrations up to 40.9 μM and achieved regeneration rate of 96% and 11.3 plantlets per explant and the addition of IBA (0.5 or 2.5 μM) improved regeneration rate up to >70%. The optimum concentration of TDZ was 37.8, 39.2 and 40.5 μM when combined with 2.5, 0.5 μM IBA and without IBA, respectively. It took 16 weeks from leave culture to complete plantlets. As a result, a protocol for “Albion” plantlet regeneration on MS medium containing high TDZ concentrations combined with IBA was developed.

Keywords: Thidiazuron, 1H-indole-3-butanoic acid, organogenesis, regeneration rate, plantlets, Fragaria × ananassa