This book presents the edited papers from a major international conference on plant breeding held at Raleigh, North Carolina, in March 1991. The contents are divided into five main sections: the gene base for plant breeding; modification of plants to tolerate environmental stresses; modification of plants to tolerate stresses due to diseases and insects; contribution of biotechnology to plant improvement; strategies for utilizing unadapted germplasm. The book will therefore Pe of great interest to research workers throughout the world in plant breeding and allied fields such as plant biotechnology.