ناصر عسکری

Lily scale-explants cultured in vitro regenerate adventitious bulblets at their base. Large scale-explants (6 × 18 mm; the basal side is 6 mm) yielded more (26%) bulblet growth than small ones (6 × 6 mm). The beneficial effect of the scale was also clear when bulblets excised from scale explants were transferred to fresh medium for additional growth. When a small piece of the original scale was left attached to these bulblets, growth increased by 33%. The growth of bulblets was highest in explants cut from the middle of a scale as opposed to the edge, and in explants cut from the basal half as opposed to the apical half. We examined the development of the scale-explants during the period of bulblet regeneration in vitro and the scale explants were physiologically very active as judged by the decrease in the amount of polysaccharides in the explant (ca.70%) and the increase in total amount of soluble sugars in the explant (ca. 40% ). In the basal scale explants, the number of starch granules was far higher than in apical scale explants. During culture, the number of vascular bundles increased in basal and apical scale explants from 6 to 3.3 to 8 and 4 bundles, respectively.