This comprehensive book provides a detailed account of the plant breeding methodology, covering particularly pre- and post-Green Revolution era. It elaborates on plant breeding and gene manipulation, utilization of self-incompatibility in developing hybrids, different plant breeding methods for development of crop varieties and hybrids in self- and cross-pollinated crops, nature of gene action and genotype–environment interaction. The text discusses gene manipulation in the crop plant and transfer of genes from wild species to cultivated crops, application of biotechnology in plant breeding, and genetic engineering and transgenic molecular markers as breeding tools and their limitations. It concludes with a discussion on physiologic breeding approach and new plant ideotype concepts which are new and emerging areas of interest in plant breeding research. The book will be of immense use to undergraduate and postgraduate students of Agricultural Sciences and Botany for their course study. Besides, research scholars and professionals will also find the book as an excellent source of reference.