ACTA BIOLOGICA CRACOVIENSIA Series Botanica 47/1: 65–73, 2005 MORPHOGENESIS OF LILIUM MARTAGON L. EXPLANTS IN CALLUS CULTURE

The effect of two plant growth regulators on the initiation of callus and regeneration of L. martagon was studied on modified MS medium. The cultures were initiated using seeds. The explants were isolated from different parts of seedlings (hypocotyls, seedling bulb, root) and adventitious bulblets. The growth regulators stimulated various types of callus. 4-amino–3,5,6-trichloropyridine–2-carboxylic acid (Picloram) induced a yellow, friable, granular callus, whereas benzyladenine (BA) alone induced a cream-white, compact callus. MS medium containing Picloram plus BA stimulated a yellow, compact, granular callus. The most useful explants for callus initiation were seedling bulbs and adventitious bulblet scales. The most efficient embryogenic callus was obtained on MS medium containing 5 µM Picloram and 5 µM BA. Histological studies showed that the embryogenic callus was formed at the epidermal cells and near vascular bundles of explants. Somatic embryos were solitary, whereas adventitious bulblets were closely connected with vascular tissue. No differences in the amount of DNA between scale tissue and callus were observed. Lilium martagon L. is an endangered species in Poland. In vitro culture techniques can play an important role in the future protection of this rare plant species