Epigenetics, plant genetic resources, and their management

Global and local changes to chromatin structure, including heterochromatin decondensation, DNA methylation, histone modifications and non-coding RNAs work together in complex ways to control gene silencing or activation through mechanisms causing chromatin changes that close or open access to genes leading to fine tuning of the genome. Variation in DNA methylation has been related to many phenomena important in relation to plant genetic resources held in genebanks. These include effects on plant phenotypes, heterosis, transgressive segregation, meiotic recombination, allopolyploidi-zation, vernalization, and abiotic and biotic stress responses.