Organelle Genomes in Plant Breeding
About this eBook
Genetics is the study of heredity and variation. The genes present in the nucleus and cytoplasm governs the heredity and variation. The nuclear x cytoplasmic interaction largely determines the phenotype, apart from the environmental factors. Gregor Johann Mendel 1865 laid the foundation for the classical nuclear genetics. The science of organelle genetics began in 1908, with the discovery of variegation of leaf colour in 4 0 clock plant Mirabilis jalapa . This finding unveiled the role of chloroplast genome in heredity and variation, for the first time in the world. The discovery of male sterility in flax Bateson and Garidner, 1921 and the possible role of mitochondrial genome in the expression of male sterility made a spectacular jump in agriculture. Knowledge of organelle genetics has paved the way for the sustained food and nutritional security through crop breeding. Our main objective in writing this text book has been to strength the knowledge of graduates and researchers in genetics and plant breeding. The quintessence of organelle genetics rests on the discovery of the presence of deoxyribo nucleic acid DNA in chloroplasts Ris and Plaut, 1962 and mitochondria Nass and Nass, 1963 . Now, it is well understood that organelle genes are capable of executing both auto-and hetero-catalytic functions viz., replication and protein synthesis. Manipulation of the organelle genomes through conventional plant breeding has gained momentum during the 20th
century. Twenty first century researches are eagerly anticipating about the impact of organelle transfer, techniques in evolving high yielding lines. The sources of illustrations data and figures are duly acknowledged then and there. The authors keep on record of their indepth gratitude to the Vice-Chancellor, Registrar and other authorities of Annamalai University for permitting to write this book. The authors are very much thankful to Prof. Dr. P. Baskaran, Dean, Faculty of Agriculture for having gone through the manuscript and offering the foreword and to Prof. Dr. Capt. J. Ganesan, Head, Department of Agricultural Botany and Prof. Dr. Kader Mohideen, Head, Department of Horticulture for their constant encouragement. We are thankful to our colleagues for their kind help in the preparation of the manuscript. We would appreciate for suggestions in improving this book.
Progress of Nuclear Gene Concept .........................1