This book describes the genetics, biochemistry, and epidemiology of host-pathogen interactions in plant disease, especially as they concern the breeding of crops for disease resistance. It analyzes a wealth of information that has not previously been recorded in other books or reviews. Some of it stems from basic surveys of disease in the field. The analysis of these surveys not only explains a great deal about host-pathogen interactions that was heretofore obscure, but also indicates directions for future research. Other data, from original papers, have now been coordinated for the first time and organized in a way that suggests new areas of research. The book contains more than fifty new tables that integrate data and relate them to general principles of host-pathogen interactions.
For plant pathologists and plant breeders concerned with the control of plant disease, the book shows how to manipulate the host and, indirectly, the pathogen in order to control disease. It analyzes records of resistance against disease that time has shown to be stable in an effort to determine what has kept this resistance stable. It also analyzes the structure of virulence in populations of a pathogen, and demonstrates how virulence can be deliberately restricted. The author updates information on the gene-for-gene hypothesis and discusses the numerical and biological implications of the hypothesis. He analyzes the structure of epidemics based on three fundamental variables: the initial inoculum, the progeny/parent ratio of the pathogen, and the latent period. The author concentrates on the progeny/parent ratio - a subject not hitherto probed in detail in the literature - and shows how to determine the type of epidemic that can occur.

As befits a volume in the Advanced Series in Agricultural Sciences, this book was written with problems of practical agriculture in mind. One of the ways of controlling plant disease is by using resistant cultivars; and from the wide literature of genetics and biochemistry in plant pathology I have emphasized what seems to bear most closely on breeding for disease resistance. This has a double advantage, for it happens all to the good that this emphasis is also an emphasis on primary causes of disease, as distinct from subsequent processes of symptom expression and other secondary effects. The chapters are entirely modern in outlook. The great revolution in biology this century had its high moments in the elucidation of the DNA double helix in 1953 and the deciphering of the genetic code in 1961. This book, so far as I know, is the first in plant pathology to be conceived within the framework of this new biology. Half the book could not have been written 20 years ago, even if there had then been available all the literature that has since accumulated on the genetics and chemistry of plant disease. The new biology is the cement this book uses to bind the literature together. Another feature of this book is an emphasis on thermodynamics.