TEN YEARS OF GROWING EXCISED TOMATO ROOTS

Abstract

MARCH 1, 1943, marked the decennial anniversary of the starting of the first uninterrupted cultures of excised plant organs²⁸. The root tip from which was derived the standard clone now used in all experimental studies on excised roots carried out in this laboratory was severed from its seedling parent on March 1, 1933. This root is still growing. From it have been made some 80,000 experimental cultures. In addition to these cultures for which increment data are available, large stocks have been maintained on which detailed records were not kept. The total measured increments represent many kilometres of growth ; the theoretical increments²⁸ amount to staggering figures (ca. 10²⁸⁰⁰ kilometres). It seems appropriate at this time to review briefly the history and behaviour of this clone.