Chloroplasts in photosynthetic organisms and mitochondria in a vast majority of eukaryotes, contain part of the genetic material of a eukaryotic cell. The organisation and inheritance patterns of this organellar DNA are quite different to that of nuclear DNA. Present-day chloroplast and mitochondrial genomes contain only a few dozen genes. Nevertheless, these organelles harbor several thousand proteins, the vast majority of them encoded by the nucleus. As a result, the expression of nuclear and organelle genomes has to be very precisely coordinated. The selection of experimental and review papers of this book covers a wide range of topics related to chloroplasts and plant mitochondria research, illustrating recent advances and diverse insights into the field of organelle genetics in plants. These works represent some of the latest research on the genetics, genomics, and biotechnology of plant mitochondria and chloroplasts, and they are of significant broad interest for the community of plant scientists, especially for those working in the subjects related to organelle genetics