배추의 子葉과 胚軸組織으로부터 植物體再分化

Shoot regeneration from cotyledons and hypocotyls of Chinese cabbage(Brassica campestris ssp. pekinensis)

The tissue culture system for obtaining high frequency shoot regeneration from cotyledonary petioles and hypocotyls of Brassica campestris ssp. pekinensis has been developed. In order to improve tissue culture system of chinese cabbage, cotyledonary petioles were cultured on MS or B₅ medium containing various combinations of hormones. MS medium supplemented with 1mg/L NAA and 4mg/L BA showed the highest regeneration frequency (63%). The 4-day old cotyledons among various explants and “Seoul baechu” among tested varieties exhibited the highest regeneration frequencies. Hypocotyl segments were regenerated efficiently when AgNO₃ (ethylene synthesis inhibitor) was added. The presence of 2mg/L AgNO₃ markedly enhanced shoot regeneration from hypocotyls. High concentration of AgNO₃(above 3mg/L) induced vitrification of regenerated shoots. Shoots were easily rooted on MS medium without hormones. Histological studies indicated the development of multiple shoot primodia from the petiolar cut ends of the explants within 3 days of culture initiation.