Effects of Gibberellic Acid on Excised Pea Roots

Abstract

IN the course of an investigation of inter-varietal differences in the growth of excised roots of field peas (Pisum sativum L. var. arvense), some effects of gibberellic acid have been observed which seem worthy of brief record. Seeds were surface sterilized with 0.1 per cent mercuric chloride and germinated for two days. Root tips (5 mm.) were excised and grown in the dark at 25° C. in Petri dishes containing the inorganic medium of Bonner and Addicott¹ with 4 per cent sucrose, vitamin B₁ (0.1 mgm./l.) and nicotinic acid (0.5 mgm./l.). Ten tips were employed in each treatment, two being grown in each dish. After seven days the roots were measured and the apical 10 mm. of each was transferred to fresh medium for a further week.