Gibberellin and the Growth of Plant Tissue Cultures

Abstract

TWO recent publications report the effects of gibberellic acid on the growth of excised plant tissues. Netien¹, working with isolates from the tuber parenchyma of Helianthus tuberosus, found a slight increase in growth at 1 p.p.m. in the absence of indolylacetic acid and a decrease at higher levels. In the presence of the auxin all levels of gibberellic acid were quite inhibitory. Schroeder and Spector² used explants from the mesocarp of mature citron (Citrus medica). They found gibberellic acid, in the absence of indolylacetic acid, caused an increase in weight at 5 p.p.m. In the presence of indolylacetic acid all levels tested resulted in increases in weight.