Transactions of the Chinese Society of Agricultural Machinery

Rising awareness of the health-promoting properties of plant-derived bioactive compounds has stimulated strong interest in vegetables with elevated anthocyanin content. Anthocyanins, as natural antioxidants, help alleviate oxidative stress, reduce the risk of chronic disease, and increase the functional value of human diets. This study aimed to improve the nutritional quality of winged bean (Psophocarpus tetragonolobus) by enhancing the frequency and intensity of purple pod pigmentation through targeted selection. A genetic improvement program was implemented using a cross between a purple-podded parent (MDM 1.2) and a green-podded parent (PLB 2.3). Population selection from the F3 to F4 generations was combined with anthocyanin quantification to assess genetic advance. Selection resulted in a marked increase in individuals expressing purple pod traits, with a 34.09% increase in pods exhibiting purple dots and a 1.71% increase in fully deep purple pods. This phenotypic shift demonstrates effective selection for anthocyanin-associated traits. Moreover, pod colour intensity showed a strong positive association with anthocyanin accumulation in other organs, including the corolla, calyx, pod wings, and seeds. Anthocyanin analysis confirmed that deep purple pods contained up to 61.37 ppm anthocyanins, exceeding the 34.54 ppm observed in the purple-podded parent. Notably, genotypes KPU 142.3 and KPU 110.1 emerged as promising lines, as both surpassed MDM 1.2 in anthocyanin concentration. These findings indicate that phenotypic selection for pod pigmentation is an efficient strategy to enhance anthocyanin content in winged bean. The study contributes to breeding approaches for nutrient-dense cultivars and is novel in integrating visual selection with biochemical validation in an underutilized legume crop. Keywords: genetic advance; winged bean; purple pod; phenotypic selection; anthocyanin content. DOI： https://doi.org/10.62321/issn.1000-1298.2025.10.1