홍띠(Imperata cylindrica 'Rubra') 기관분화에 의한 기내대량증식

In vitro Multiple-propagation of Wolly Grass (Imperata cylindrica 'Rubra')

This study describes an efficient and widely applicable droplet-vitrification following cryopreservation for shoot tips of (Fragaria x ananassa DUCH. cvs. 'Derunoka' and 'Jumbo pure berry'. The shoot tips of strawberry were precultured in Murashige and Skoog (MS) liquid medium supplemented with sucrose (0.3-0.7M). Precultured explants were treated with loading solution (LS, C4) containing glycerol 17.5% and sucrose 17.5% for 40 min and exposed to dehydration solution (B1) containing 50% of glycerol and 50% of sucrose for 60 min at <TEX>$25^{\circ}C$</TEX>, and then transferred onto droplets containing <TEX>$2.5{\mu}l$</TEX> PVS3 on sterilized aluminum foils (<TEX>$4cm{\times}0.5cm$</TEX>) prior to direct immersion in liquid nitrogen (LN) for 1 h. The highest regeneration rate (%) was obtained when shoot tips were precultured with treatment-2 (exposing of shoot tips to MS + 0.3M Sucrose for 30 h and then treated with MS+0.5 M sucrose for 16 h) at <TEX>$25^{\circ}C$</TEX> in both the cultivars. The viability of cooled samples, followed by culturing on MS medium for 4 weeks was 77.8% and 60.0% for 'Derunoka' and 'Jumbo pure berry', respectively. This result shows droplet-vitrification would be a promising method for cryobanking strawberry germplasm.