We propose a radically new approach to sex change of plants - via demethylation and methylation of chromosomal DNA - based on nascent theoretical work on evolution of sex determination in all plants and animals. This approach should not only result in sex change, but also in mutations (thereby increasing genetic variation) and regeneratation of whole plants from tissue-cultured cells. This should result in propagation of many viable and genetically variable individuals of both sexes with the desired parenthood of mitochondrial and chloroplast DNA. Thus, remarkably, artificially induced demethylation and methylation of chromosomal DNA may allow for the re-establishment of viable populations of plants from a single clone of a dioecious species. We propose testing and applying this theory to conservation of the cycad Encephalartos woodii, for which only a single male clone exists, sex change has never been induced, and roots and shoots have never been regenerated from tissue culture callus.

Key words: azacytidine, conservation, Encephalartos woodii, epigenetic, methylation and demethylation