CHANGES IN THE RESPONSE OF CARROT ROOT CALLUSES TO THE ROOT EXTRACT OCCURRING DURING THEIR SUCCESSIVE CULTURES

Abstract

Alcohol extract of carrot root promoted the growth of the carrot root callus which had been succesively cultured for more than 18 months (CCL) on the medium containing WHITE'S inorganic salts, sucrose, yeast extract and 2, 4-D, but only a weak promotion was observed for the growth of the carrot root callus which had been cultured for less than 14 months (CCS). The active substances were fractionated by Amberlite IR-120 and Amberlite IRA-400 into four fractions; C, D, E, and F. Each fraction seemed to act synergistically to produce the effect of the whole carrot root extract on the growth of CCL. Fraction F of the carrot root extract, which was adsorbed by Amberlite IRA-400 but not by Amberlite IR-120, promoted the growth of CCL in the presence of other fractions, but had no effect on the growth of CCS. So the different responses to the alcohol extract of the carrot root calluses having different lengths of successive culture period seemed to depend mainly on the ability of responding to fraction F. Using four strains of carrot root calluses of different origin, it was ascertained that different responses of carrot root calluses to fraction F depended on the length of their culture and not on their strain-specific characters. The substances active for the growth of CCL in the carrot root extract passed through a dialysis membrane. These substances were little affected by autoclaving and remained in the aqueous layer when shaken with several organic solvents: n-butanol, ethyl acetate, chloroform, benzene, ethyl ether and carbon tetrachloride. Alcohol extract of carrot root also promoted the growth of carrot root explant, tobacco stem callus and sunflower crown gall tissue.