Molecular Approaches for Harvesting Natural Diversity for Crop Improvement

Abstract

The evolution of new species revolves around the natural as well as induced genetic variation created through revolutionary and conservative forces. Evolution and domestication are the two important phenomenon which occurred in nature, while domestication acts as a signature of evolution for harnessing the important diversification traits in crop plants which plays an important role in global food security target through crop improvement. Conservation of natural genetic diversity is the utmost importance for tackling future biotic and abiotic threats for achieving global food and nutritional security. To feed the approximately 10 billion world population by 2050, it is necessary to increase the yield of staple crops up to 70-110%. Therefore, utilization of natural genetic diversity present in the form of wild relatives (CWR), landraces, and modern cultivars is indispensable for achieving food security which is of prime importance for crop improvement programs. Crop genetic resources with a broad genetic base are the valuable assets in crop plants which can be utilized through base-broadening approaches such as pre-breeding and core and mini-core collection. Besides these, a wide array of molecular approaches is available for exploitation and harnessing of natural diversity for achieving higher genetic gains for future food and nutritional security. Through this chapter, we have tried to discuss the domestication events with respect to genetic architecture in crop plants during the course of evolution, crop improvement for food and nutritional security, role of crop genetic resources and their importance, genetic bottlenecks responsible for narrowing down of genetic diversity, significance of conservation of natural variation, and base-broadening conventional approaches. Various molecular approaches (forward and reverse genetics) with genetic modification, genome editing, and sequencing methodologies for harnessing the natural variation for maximization of genetic gain and future scope of natural diversity from plant to crop with three Bs (biotechnology/biodiversity/biomimicry) and optimistic approach of conservation of diversity for future sustainable crop improvement are also discussed.