UTILIZATION OF EMBRYOGENIC CELL CULTURES FOR THE MASS PRODUCTION OF BULBLETS IN ORIENTAL AND EASTER LILIES

Abstract

To utilize an embryogenic cell culture for bulblets production in Oriental and Easter lilies, methods of callus induction, multiplication and bulblet production were investigated. The sliced bulb scales of a Lilium longiflorum hybrid (longiflorum x fomolongi) and Oriental hybrids ('Marco Polo', 'Casa Blanca', 'Le Reve') were cultured on MS solid medium (3% sucrose, 0.3% Phytagel) supplemented with 2,4-D, dicamba or picloram at the concentrations of 1, 3, 6 and 9 mg L -1 . The most embryogenic calli were produced with 3 mg/L of picloram in the Oriental hybrids. The embryogenic cells of the Oriental hybrid 'Marco Polo' were cultured in an air-lift-type 20-L bioreactor using liquid MS medium (5% sucrose, pH 5.8) supplemented with 2 mg L -1 of picloram, and transferred to culture boxes (96x96x90 mm) containing 100 ml of hormone-free MS agar medium (0.3% Phytagel, 9% sucrose) for bulblet formation. Bulblets larger than 5 mm in diameter were produced in 20 weeks and planted in greenhouse after 8 weeks of storage at 4°C. They made bulbs of 6 to 9 cm in circumference in a greenhouse in 8 months. Adult plants of L. longiflorum, regenerated from the cells maintained over 4 years produced mostly morphological variants of flower deformities, and among the plants derived from 6-month-old callus of the Oriental hybrid 'Marco Polo', few variants were found. Therefore, bulblets of Easter and Oriental lilies can be produced in quantity relatively in short periods using embryogenic cell cultures.