Key Determinants of Seed Size for Enhancing Genetic Gain in Legumes

Legumes play a pivotal role in human nutrition due to their high nutritional value, especially protein content. Therefore, enhancing the productivity of grain legumes is desirable for ensuring food and nutritional security. Seed size and seed weight are key factors influencing productivity. This article consolidates the substantial amount of research conducted to uncover the molecular signatures associated with seed size into a structured format, providing a one-stop platform of available resources for enhancing genetic gains in legumes. The advent of NGS technologies enabled the decryption of genomes and transcriptomes of important grain legumes. Moreover, molecular signatures such as SSRs, SNPs, transcription factors, methylation patterns and so forth scanned from phenotypically and genotypically well-characterized natural and mapping populations helped identify the QTLs, MTAs and candidate genes associated with seed size. Many of these QTLs and candidate genes have been utilized in marker-assisted breeding for achieving larger seeds and enhanced yield in legumes. Besides, the characterization of legume orthologs of candidate genes from other crops using different omics approaches helped in understanding the regulatory pathways involved in seed size determination in legumes. This review provides a direction for the effective utilization of available resources to enhance legume productivity.