Induction of primary root curvature in radish seedlings in a static magnetic field

Primary roots of radish (Raphanus sativus L.) seedlings were exposed to an inhomogeneous static magnetic field generated by a permanent magnet, during continuous rotation on a 0.06 rpm clinostat, thereby reducing the unilater al influence of gravity. The roots responded tropically to the static magne tic held with the tropism appearing to be negative. These roots responded s ignificantly (P < 0.05) to the south pole of the magnet. The significant tr opic response was found for a magnetic flux density of 13-68 mT, for a fiel d gradient of 1.8-14.7 T/m, and for the product of magnetic field and field gradient of 0.023-1.0 T-2/m. A small, but insignificant, response of the r oots to the north pole has also been found. <(c)> 2001 Wiley-Liss, Inc.