Rooting of micropropagated calla lily

The effect of exogenously supplied NAA on Zantedeschia 'Ruby' adventitious root formation and shoot growth in vitro was studied by applying 0.01-10.0 mg I1 concentrations. The bud-induction medium consisted of the basal medium of Murashige and Skoog with 30 g I"1 of sucrose, 3.0 mg I"1 of BAP and 6 g I1 of agar (Sigma Chemical Co. Ltd., London, U.K.), pH 5.6. Rapidly multiplying shoot clumps were cultured on an MS multiplication medium containing 3.0 mg I"1 of BAP for 6 subcultures and then were subdivided and placed on a similar medium with BAP concentration reduced to 0.3 mg I"1 Microshoots (2-3 cm in length) were transferred to the medium with 0.0-10.0 mg I1 of NAA for 40 days. Experiments were conducted on the effect of varying NAA concentration on the adventitious root induction and shoot quality - root quantity, height of shoots, etc. Transfer of plantlets from MS nutrient medium containing 0.3 mg I"1 of BAP to the medium containing various NAA concentrations stimulated growth of shoots only after the influence of NAA concentration of 0.01-0.1 mg I"1. Under the influence of 5.0-10.0 mg 1"' of NAA the percentage of explants with roots on the MS medium decreased respectively 23.9-49.4%. Shoot length was best affected by NAA con¬centration of 0.1 mg I"1. NAA concentration of 0.01 mg I'1 was the optimum one for the best development of plants with branching rootsVytauto Didžiojo universitetasŽemės ūkio akademij