A Highly Efficient In Vitro Regeneration System for Pearl Millet (Pennisetum glaucum) Variety "Shandaweel-1" Using...

Pearl millet (Pennisetum glaucum) is a widely cultivated C4 cereal crop in tropical and subtropical regions, serving as a food and feed source in developing countries across Africa and Asia. Despite its agronomic importance, research efforts aimed at developing improved millet varieties under the current climatic changes remain limited, particularly in Africa, including Egypt. This study aimed to establish an efficient regeneration system for the "Shandaweel-1" Egyptian pearl millet variety using immature inflorescences as explants. Six different callus induction media (CIM) treatments were evaluated for their effects on somatic embryogenesis, callus type, vitrification rate, and regeneration efficiency. Among the tested treatments, Murashige and Skoog (MS) media additionally supplemented with 1.0 mg L^-1 of l-proline, 1.0 mg L^-1 of l-asparagine, 10 mg L^-1 of silver nitrate (AgNO₃), 0.32 mg L^-1 of copper sulfate (CuSO₄), 1.0 mg L^-1 of 2,4-dichlorophenoxyacetic acid (2,4-D), and 0.5 mg L^-1 of 6-benzylaminopurine (BAP) produced a high callogenesis rate (93%) and the highest regeneration efficiency (47.6%). The combination of l-proline and l-asparagine enhanced the callus quality and regeneration potential more effectively than casein hydrolysate alone, whereas AgNO₃ addition did not have any significant impact on the vitrification or callogenesis rates. This study represents the first successful establishment of an in vitro regeneration system for an Egyptian pearl millet variety, providing a valuable platform for future genetic modification aimed at enhancing stress resilience and crop productivity.