Plant reproductive biology has undergone a revolution during the past five years, with the cloning, sequencing and localization of the genes important in reproduction. These advantages in plant molecular biology have led to exciting applications in plant biotechnology, including the genetic engineering of male sterility and other reproductive processes. This book presents an interesting and contemporary account of these new developments from the scientists in whose laboratories they have been made. The chapters focus on two areas: the molecular biology of self-incompatibility, which is the system of self-recognition controlled by the S-gene and related genes; and the cellular and molecular biology of pollen development and genetic dissection of male sterility. Some chapters feature Arabidopsis, with its unique genetic system. Reproduction is vital for seed production in crop plants, and this book presents new approaches to manipulate plant breeding systems for the 21st century.