Influence of growth regulators and nitrogenous compounds on in vitro bulblet formation and growth in oriental lily

Abstract

The influence of growth regulators and nitrogenous compounds on in vitro bulblet formation and growth was studied in two hybrids of <i>Lilium</i>. Bulbscales isolated from pre-cooled bulbs of hybrids Rosato and Marco Polo were used. The basal portion with plate (5 × 6 mm) of inner bulbscales was cultured on Murashige and Skoog (MS) medium containing 0.5 or 1 mg/dm<sup>3</sup> naphthaleneacetic acid (NAA) and/or benzyladenine (BA). The presence of NAA (0.5 mg per dm<sup>3</sup>) showed higher explant regeneration, producing about three bulblets per explant as compared to control. About four bulblets per explant were produced at both concentrations of BA. The bulblets with significantly higher fresh weight were obtained on medium containing NAA. Approximately a three-fold increase of bulblet fresh weight was observed with all the concentrations of TDZ in both cultivars. The bulblets cultured with nitrogenous compounds after attaining the size of 14−16 cm flowered during the second year of the growing period without any phenotypic variations.