Enhancing Abiotic Stress Response in Pigeonpea

Pigeonpea ( Cajanus cajan (L.) Millsp.) is an important food legume crop cultivated throughout the tropics and subtropics. The major abiotic stresses limiting the productivity of this crop include waterlogging, drought stress, high and low temperature, low soil fertility, soil salinity/acidity, and deficiency of micronutrients. These stresses disrupt physiological processes, including osmotic adjustment and cellular homeostasis, leading to substantial yield losses. Climate change exacerbates these challenges by intensifying water stress and temperature extremes, further threatening pigeon pea cultivation, particularly of long-duration pigeonpea in the north-east plains of India. Phenotyping is vital for identifying and selecting tolerant genotypes with enhanced resilience to abiotic stresses and pinpointing traits that are associated with tolerance. Characterizing key traits through phenotypic analysis can provide big data-based decision support for breeding and cultivation practices. Advances in plant phenomics, especially high-throughput phenotyping (HTP), have revolutionized the study of stress tolerance, enabling precise and nondestructive assessment of traits such as growth, water productivity, and photosynthesis. A nexus among plant phenomics tools, conventional breeding techniques, and high-throughput genotyping (HGP) is essential for developing climate-resilient pigeon pea varieties for a sustainable farming system. This chapter explores the role of phenomics tools in understanding the mechanisms of abiotic stress tolerance and their potential use for accelerating pigeonpea improvement efforts to enhance climate resilience.