The book is selective and not an encyclopaedic account of the molecular genetics of all areas of plant biology. Topics have been chosen partly because of their intrinsic interest and importance in plant biology and partly because of the state of molecular knowledge in that topic. Emphasis has been given to the use of genetic analysis in combination with molecular techniques. This means that studies which have used either the selection and analysis of mutant plants or transformation technology and analysis of transgenic plants have been given a prominent place in the book and this choice reflects the power of this type of analysis in research of plant processes. A relatively small number of annotated references are given for each chapter also has a list of major learning objectives. These are intended to help students to assess their knowledge and understanding of each topic. They are all based on the material of the chapter but may expect the student to integrate the information in a way that does not involve a straight recapitulation of the chapter. The book is organized so that Part 1 provides information about plant genomes and their inheritance and expression. Part 2 deals with the biology of Agrobacterium tumefaciens and the use of this bacterium in plant transformation. This topic is given an early and prominent position in the book because of the importance of this technique in many plant molecular studies. Part 3 covers a number of different topics in plant biology and Part 4 gives an introduction to the application of plant molecular genetics in plant biotechnology. The book ends with a short description of the widespread debate about the possible problems of what has been called 'plant genetic engineering'.