This book provides a comprehensive overview of the wild relatives of crops and cultivated species found in India, covering their distribution, phylogenetic relationships with cultivated species, traits that are of economic and breeding value, and the perceived threats. It highlights the opportunities the wild relatives of cultivated species offer in terms of new genes and allelic variability, as well as several other exploitable economic and environmental benefits that can be harnessed with their conservation and cultivation. This helps facilitate their use - both directly and as part of the breeding program for related cultivated species, filling the gaps of genetic variability in the primary gene pool. It also discusses how they can be used in breeding programs using conventional technologies and the biotechnological approaches of recombinant DNA. Transfer of natural genes using recombinant DNA, known as Cisgenesis, can accelerate the process of incorporating these natural genes without genetic drag of undesirable features and biosafety concerns, and beyond taxonomic boundaries, in response to the demand for new cultivars to meet the challenges of climate change and ever-growing human population.