Plant breeding is the practice of growing plants with improved traits for achieving nutritional and economic advantage, and food security. Genes are the determiners of the qualitative and quantitative traits that a plant exhibits. While desirable characteristics can be achieved through selective propagation or crossing, modern plant breeding applies the techniques of molecular biology to select and insert the traits required. This application of molecular biology or biotechnology for plant breeding is known as molecular plant breeding. The important areas of molecular breeding are genomic selection and marker assisted selection, genetic engineering, QTL mapping or gene discovery and genetic transformation. Molecular plant breeding is an emerging field of science that has undergone rapid development over the past few decades. The various studies that are constantly contributing towards advancing technologies and evolution of this area of study are examined in detail in this book. It will help new researchers by foregrounding their knowledge in this emerging field.