The potential in the area to respond to consumer demands and address public health issues through diet, has brought about the impetus to do further research by government, industry and research institutes to substantiate the science behind the health benefits from plant constituents. Marker Assisted Selection hold great potential for plant breeding as it promises to expedite the time taken to produce crop varieties with desirable characters. Progress has been made in mapping and tagging many horticultural important genes with morphological, biochemical and molecular markers which form the foundation for marker assisted selection in crops plants. They offer great scope for improving the efficiency of conventional plant breeding by carrying out selection not directly on the trait of interest but on molecular markers linked on those traits. Plant cell and callus culture systems have been emerged most potential area of bio processing and production of useful metabolites of nutraceutical importance. These methods have been advanced through bioreactor technology. Research and development is critical to the rapidly developing field of functional foods and nutraceuticals. Producers want new opportunities that increase farm income; processors want value-added food products, health ingredients and new uses for agricultural production, by-products and new products for new and existing markets. Consumers (worldwide) want increased assurance of the safety and quality of the food system and enhanced environmental performance of the agriculture and agri-food sector. Provinces and communities are seeking economic development opportunities for horticulture. This book will be helpful in better understanding, utilization of crop diversity, underutilized crops, and their residues and improvement in PHT and development of new functional food with greater use of bioactive compounds and other quality traits.