Articles
GROWTH OF BULBLETS OF LILIUM SPECIOSUM IN VITRO AND IN SOIL
Relative (bulb weight as percentage of plant weight) and absolute bulb weights were determined in plantlets regenerated under various conditions.
High absolute weights occurred after protracted culture in vitro, in the dark or at high concentrations of sucrose or MS-nutrients.
High relative weights (i.e. reduction of leaf formation) occurred at high temperature, in the dark, or at high concentrations of sucrose or osmoticum.
Abscisic acid (ABA) and paclobutrazole (an inhibitor of gibberellin synthesis) completely blocked leaf formation, whereas fluridone (an inhibitor of ABA synthesis) blocked bulb formation.
Gibberellins (GA3 or GA4+7) and other growth regulators, viz., ethylene, auxin, cytokinin, and methyl jasmonate had no or no distinct effect.
Cold-treated bulblets were planted in soil.
The dry-weight increase after planting was promoted by a cold treatment, also in bulblets regenerated at 15°C that did not require a cold treatment to achieve sprouting.
The dry-weight increase of cold-treated bulblets in soil was much larger than the increase in vitro on scale explants.
This may be caused by the cold treatment or by insufficient availability of nutrients in vitro.
Abbreviations: ABA, abscisic acid; GA, gibberellin A; fluridone, 1- methyl-3-phenyl-5-(3-[trifluoromethyl]phenyl)-4-(1H)-pyridone;