EFFECT OF COPPER ON SHOOT AND ROOT REGENERATION IN WHEAT, TRITICALE, RAPE AND TOBACCO TISSUE-CULTURES

CuSO4 (0.1-100 mu M) significantly enhanced shoot regeneration from ca lli of wheat and triticale and of tobacco leaf disc cultures. In cultu res of wheat and triticale, CuSO4 also stimulated root formation. When equal concentrations of CuSO4 were applied in different media, it was found that the components of the basal media had only modifying effec ts. CuSO4 pretreatment promoted plant survival when regenerated wheat plants were transferred directly to potting soil. In contrast with CuS O4, AgNO3, which also stimulated shoot regeneration, inhibited rooting in wheat and triticale. In Brassica napus callus cultures, AgNO3 stro ngly increased morphogenesis, whereas CuSO4 had no significant effect.