Genetic improvement and bioactive potential of rice bean (Vigna umbellata) for climate resilience and sustainable agriculture

The integration of underutilised orphan crops into food systems can reduce the reliance on major crops for global food security and support adaptation to climate change. Major crops are increasingly susceptible to climate effects such as drought, warming temperatures, floods, and unfavourable growing conditions. Rice bean, for example, is a minor crop that is well adapted to hot, dry climates and is highly nutritious, high-yielding, and resistant to various biotic stresses. Rice bean also contains bioactive compounds like phenolic acids and flavonoids that confer resistance to insects and diseases but they also have health benefits. Despite these advantages, rice bean faces adoption barriers linked to traits such as pod shattering, indeterminate growth, lengthy cooking times due to seed hardness, and untimely pod maturity. Therefore, utilising modern tools to explore its genomic and bioactive potential is essential, especially given the limited literature on rice bean use across different regions. This review examines current research on rice bean's genetic diversity, nutritional value, environmental tolerance, bioactive properties, and breeding strategies, aiming to unlock the crop's full potential. This will guide breeding efforts, inform future studies, and provide solutions for leveraging rice bean's inherent qualities and transferring knowledge to other crops. Integrating agro-morphological traits, bioactive potentials, and genomic resources through advanced breeding techniques could significantly boost rice bean's global adoption across diverse regions, enabling region-specific climate adaptation in breeding programs.