Drought Adaptation in Pearl Millet (Pennisetum glaucum (L.) R. Br.): Physiological, Molecular and Genetic Approaches

Pearl millet, a cereal crop grown in arid and semiarid regions, faces significant constraints due to drought. As an essential source of food and fodder in water-limited environments, its production is crucial for ensuring food security in regions like Africa and the Indian subcontinent. However, drought stress can lead to substantial yield losses, making it necessary to develop pearl millet cultivars with enhanced adaptation to drought. To achieve this, understanding the drought adaptive mechanisms and their interactions with genotypes and the environment is essential. This chapter focuses on the progress made in improving drought adaptation in pearl millet through physiological, molecular, and genetic approaches. The research highlights the importance of environmental characterization and revised production zones for pearl millet cultivation in rain-fed systems. By using crop simulation modeling techniques, the study provides insights into the diverse agro-climatic conditions and production constraints across different target population environments (TPEs). The proposed zonation revision facilitates the development of targeted breeding strategies and optimization of production systems. Furthermore, the chapter discusses physiological traits related to drought adaptation, such as soil water conservation, canopy development, and water use efficiency. It also explores molecular approaches, including the role of aquaporin genes in regulating water transport and transpiration rate in pearl millet. In addition, this chapter also focuses on genetic approaches in pearl millet highlighting DNA markers and QTLs associated with drought adaptation traits, providing valuable targets for breeding programs.