The present book is the fourth in the Plant Breeding Series published by Chapman & Hall, and extends the aspects covered in the three earlier volumes, particularly with its focus on ecological aspects related to breeding. The first book, Plant Breeding: Principles and prospects, edited by Hayward, Bosemark and Romagosa, set a wide ranging, authoritative and broad view of techniques and approaches being adopted in modem plant breeding. The second, Selection Methods in Plant Breeding, by Bos and Caligari, was written to help further secure the scientific basis underlying selection methods as applied in practical plant breeding. The third, Statistical Methods for Plant Variety Evaluation, edited by Kempton and Fox, ensured a strong foundation in the design of trials and the subsequent handling of data, upon which successful breeding is based. It followed the successful formula of the first book in being based on a course taught in Zaragoza.This fourth book starts by giving the underlying philosophy and modelling needed to tackle the ubiquitous genetical variation with which all breeders are confronted, namely quantitative variation. The nomenclature used is new and follows that agreed by a group of us, to be mainly based on that used more commonly by animal breeders than by plant breeders. It was agreed in discussion that this nomenclature has a more direct logic (e.g. additive variation is designated as a, dominance is d, and so on). This led to Kearsey and Pooni's book being the first published using this notation (The Genetical Analysis of Quantitative Variation, by M.J. Kearsey and H.S. Pooni, Chapman & Hall, 1996, ISBN 0412609800) which needed extension from that in common use because of the sophisticated extensions to the theory and analysis already devised by those working with such variation in plants. This approach is continued here and used to give this present book its useful place in providing a valuable interface between the theory and practice of plant breeding (although translation between this and the earlier notation is not too difficult).As noted in all the earlier books, the need for plant breeders to be successful has never been greater. The potential future population growth must fill all of us with concern and is a clear indication of the absolute need for success in plant breeding. This point is picked up again by the present authors in various places within the text and the authors further emphasize this by their appreciation of those concerns in the concluding chapter on 'Genetic resources, genetic diversity and ecogeographic breeding'. The use of a range of traditional and modem techniques must ultimately be united in the genotypes we grow, to ensure their adaptation to their place in the environment in which they are required to grow and in which we share their existence.The present book is aimed, as the other three were, not only at the student who is learning the subject of plant breeding but also at the breeder who is trying to improve our crop species. It has been written to make clear...