Influence of 50 Hz electromagnetic fields on recurrent embryogenesis and germination of cork oak somatic embryos

Plant tissue culture techniques are carried out under environmentally contr olled conditions in phytotrons. However, electric components of phytotrons generate electromagnetic fields that may act as a environmental factor infl uencing plant growth and morphogenesis. Isolated somatic embryos of Quercus suber, picked from embryogenic lines, were chronically exposed to a 50 Hz and 15 mu T electromagnetic field generated in a Helmholtz-coil system for 8 weeks, in order to examine if the extremely low frequency (ELF) magnetic field (MF) affected the morphogenic behaviour of embryogenic cultures durin g recurrent embryogenesis. Germination of somatic embryos from genotype G7. 1 was carried out under the same electromagnetic field, and also under cond itions in which the local geomagnetic field was suppressed. The ELF MF did not influence the growth of embryogenic clumps of the assayed genotypes, bu t reduced the number of detachable embryos produced by genotype G3.27. The ELF MF did not modify the percentages of germination or plant formation of somatic embryos. However, somatic embryos had better germination when cultu red under the suppressed geomagnetic field condition.