Heritability, Correlation, and Path Analysis for Selecting Superior Purple Winged Bean Genotypes (Psophocarpus tetragonolobus L.)

Winged bean (Psophocarpus tetragonolobus L.) is a nutrient-rich tropical legume with considerable potential to improve food security in tropical regions. However, breeding programs for purple-podded winged bean remain limited due to insufficient information on key genetic parameters. This study aimed to assess heritability, expected genetic gain, trait correlations, and path analysis in advanced purple-podded winged bean lines. Ten breeding lines derived from crosses of Indonesian landraces were evaluated using a randomized complete block design with three replications. Traits observed included days to flowering, days to harvest, fruit set, pod width, pod length, pod weight, pod weight per plant, number of seeds per pod, and yield potential. The results revealed high broad-sense heritability (>0.5) for all traits, with the highest values observed for pod length (0.96), pod width (0.95), and fruit set (0.90). Expected genetic gain was highest for fruit set (35.20%), pod weight per plant (34.44%), and yield potential (34.44%). Correlation analysis indicated strong positive relationships between days to flowering and days to harvest (r = 0.90), while yield potential showed a perfect correlation with pod weight per plant (r = 1.00). Path analysis revealed positive direct effects of fruit set (0.478) and pod weight (0.310) on pod weight per plant, whereas number of seeds per pod had a negative direct effect (-0.429). Genotypes MNN 1122 and PLB 2324 exhibited the highest yield potentials (8.58 and 7.63 t ha^-1, respectively). These findings provide important genetic insights for the development of high-yielding purple-podded winged bean varieties.