Exploring agro-morphological diversity and superior genotypes in Beta vulgaris var. bengalensis L.: a two-year comprehensive study of an underutilized traditional green leafy vegetable of Northern India

Limited exploitation of genetic variability in palak ( Beta vulgaris var. bengalensis L.), a nutritionally important yet underutilized orphan leafy vegetable, has hindered the development of high yielding, stable and nutrient-rich cultivars. To address this gap, the present study comprehensively dissected agro-morphological diversity and identified superior genotypes using robust statistical and multivariate approaches. Forty diverse genotypes were evaluated over two consecutive winter seasons (2023–24 and 2024–25) under field conditions. Significant genotypic variation (p < 0.01) was observed across all quantitative traits, confirming a broad genetic variability. High genotypic and phenotypic coefficients of variation, coupled with elevated heritability and genetic advance, were recorded for various economic traits indicating strong additive genetic control and high selection efficiency. Multivariate analyses revealed that the first two principal components collectively accounted for up to 74.06% of total variation, with key contributions from plant height, leaf architecture and seed traits. Hierarchical cluster analysis consistently delineated four distinct clusters, consistently identifying Cluster IV (PP8, PP20, and PP44), which exhibited superior multi-trait performance. Significant positive associations among key leaf yielding traits supported their use as reliable indirect selection indices. Overall, genotypes PP13, PP20, and PP44 emerged as genetically superior, stable, and promising lines for use in future breeding programs. The findings provide a robust scientific foundation for targeted selection, germplasm utilization, and genetic enhancement of palak.