ANDROGENESIS IN HORDEUM-VULGARE L - EFFECTS OF MANNITOL, CALCIUM AND ABSCISIC-ACID ON ANTHER PRETREATMENT

Pretreatment-induced androgenesis of Hordeum vulgare L. cv. Igri was i nvestigated in order to find factors which control optimal plant produ ction. The influence of what is called pre-medium and of the concentra tion of both mannitol and calcium were studied, Increasing concentrati ons of each of the compounds, also resulting in a higher osmolality, i mproved both embryo like structure (ELS) and plant productions. Optima l ELS production was obtained upon anther pretreatment in about 20 mM CaCl2 while optimal plant production was obtained with anther pretreat ment in about 30 mM CaCl2. In addition, it was observed that calcium c ould be replaced by potassium ions. Since abscisic acid (ABA) is invol ved in several developmental processes and is known to be induced by v arious stresses, we studied the effects of ABA and the ABA biosynthesi s inhibitor fluridone on the induction of androgenesis. Although exter nal addition of ABA did not significantly affect both ELS and plant pr oductions during pretreatment, addition of fluridone could dramaticall y reduce the production of plants. The possible mechanism of pretreatm ent in induction of androgenesis is discussed. (C) 1997 Elsevier Scien ce Ireland Ltd.