IMPROVEMENT OF ACONITUM-NAPELLUS MICROPROPAGATION BY LIQUID CULTURE ON FLOATING MEMBRANE RAFTS

An efficient method was developed using floating membrane rafts (Lifer aft(TM)) for the micropropagation of Aconitum napellus (Ranunculaceae) , a cut flower crop with a low natural propagation rate. This was achi eved by introducing shoot tips into culture on Murashige and Skoog's ( 1962) solid medium, or liquid medium-supported rafts, supplemented by different levels of benzyl adenine (BA). Optimum shoot proliferation o n solid medium required 4mg/l BA, whereas for explants supported on ra fts optimal proliferation was achieved at 0.25mg/l BA. Maximum shoot p roliferation was found using the floating rafts (propagation ratio of 4.2 per month), 45% higher than the maximum value on solid medium. A s imilar value could be obtained on solid medium after a period of 2 mon ths. The optimal response to BA was similar for fresh weight gain and shoot length. Growth in a shallow layer of liquid in shake flasks give s a similar shoot multiplication rate to that on floating rafts; howev er, submerged leaves brown and die.