THE EFFECTS OF GIBBERELLIC ACID AND CYCOCEL ON THE GROWTH OF CULTURED LEAF TISSUE

Abstract

Meristematic sections of Pteris cretica var. wimsetti leaves were cultured in various nutrient media. Gibberellic acid (GA), in the presence of sucrose, brought about a significant increase in area compared with controls over a 4-week period. GA also prolonged meristematic activity for up to 8 months, the tissue increasing many times in area and dry weight during this interval. GA significantly increased total cell number, while having no effect on the size of individual epidermal cells. Cycocel ((2-chloroethyl) trimethylammonium chloride) strongly inhibited the growth of leaf sections, but this inhibition was completely reversed by GA. The possible role of gibberellins in leaf morphogenesis is discussed.