Effects of High and Very Low Magnetic Fields on the Growth of Hairy Roots of Daucus carota and Atropa belladonna

Hairy roots of Daucus carota and Atropa belladonna, which wereinduced by inoculation with Agrobacterium rhizogenes that harboredthe Ri plasmid, were cultured on Murashige and Skoog's solidmedium in magnetic fields of 5 kgauss or 50 µgauss. Thegrowth rate of roots exposed to 5 kgauss was 25% greater thanthat of the control (0.01 kgauss). In the case of A. belladonna,the growth rate of the roots cultured in a field of 50 µgausswas 40 to 56% greater than that of the control (0.5 gauss).In D. carota, after more than 40 h of incubation, growth ratesin both sets of conditions (50 µgauss and control) werethe same. ⁴Present address: Biological Laboratory, Faculty of Education,Yamagata University, Yamagata, 990 Japan. (Received August 24, 1988; Accepted March 23, 1989)