Abstract
Cajanus cajan (L.) Millsp. is an adaptable, resilient, and nutrient-dense grain legume with qualities that can help agricultural systems become more sustainable in subtropical and tropical regions. Extremes in moisture, temperature, photoperiod, and mineral-related stressors are the most significant that encounter throughout the life cycle. Different stress slows down the plants’ growth by upsetting its typical physiology and morphology. Inefficient conditions can occur sequentially or simultaneously in environments, and plants have evolved defense mechanisms to continue to grow and survive under less-than-ideal edaphic and climatic factors. Although various genotypes of pigeonpea have been identified that are tolerant to heat, drought, and waterlogging, new empirical evidence reveals that genotypic changes have been detected for all of the abiotic stimuli in this crop. Furthermore, to enhance tolerance, breeding techniques or methods such as marker features, including extensive hybridization, double haploids, tissue culture, somaclonal variants, genetic transformation, and marker-assisted breeding, have been employed to lessen the effect of these stressor. These methods help in the development of enhanced germplasm with abiotic stress tolerance and disease resistance, resulting in higher crop quality and production. This chapter focuses on different abiotic stressors and the methods that have been employed to help pigeonpea to overcome environmental constraints.