NAPHTHALENE ACETIC ACID IN THE ALLIUM TEST

Abstract

N 1939 one of us studied the effect on Alliuni root meristems of I various synthetic phytohormones, among them naphthalene acetic acid. The main histological and cytological effects were briefly described. Special attention was directed to the occurrence of polyploid mitoses in the old cortical tissue. It was demonstrated that the polyploidy in this case was of the endomitotic type, and the inducing factor was thought to be the growth in cellular volume. It could not be decided at that time whether the phytohormoiie caused this chromosome doubling or only acted as a detector of a polyploidy already induced by the natural growth of the cortical cells. After that, spontaneous chromosome doublings of the same type were demonstrated in differentiated tissues of many plants, among them Allium (BERGER and WITKUS, 1946).