Harnessing the Genetic Diversity of Yam Bean (Pachyrhizus spp.) for Crop Improvement

Abstract

The yam bean (Pachyrhizus spp.) is a climate-resilient, multipurpose underutilized legume that holds significant potential for global food security and sustainable, low-input farming. Its nutrient-dense tubers rich in protein, vitamin C, and folic acid coupled with its ability to enhance soil fertility through symbiotic nitrogen fixation, make it an ideal crop for diversified agricultural systems. Genetic research confirms a stable diploid nature (2n=22) across species such as P. erosus, P. tuberosus, and P. ahipa, providing a foundational framework for systematic improvement. Breeding efforts have successfully evolved from classical germplasm selection, yielding high-performing varieties like Rajendra Mishrikand-1 (RM1), to interspecific hybridization and mutation breeding via gamma radiation and EMS to optimize plant architecture and dry matter. While biotechnological tools like SSR markers and micropropagation have accelerated diversity assessments, the crop’s commercial potential is still limited by seed toxicity, rapid viability loss, and yield instability. Addressing these constraints through integrated genomic innovation and marker-assisted selection is essential to transitioning this versatile legume into a mainstream global commodity.