Genetic and biochemical traits diversity in germplasm of Indian Himalayan radish (Raphanus sativus L.)

Abstract

This study evaluated 67 radish genotypes over two consecutive years (2021–22 and 2022–23) to assess genetic variability for important morphological, yield, and biochemical traits and to identify responsive genotypes for crop improvement. Pooled analysis of variance revealed highly significant differences for root length, root width, plant spread, days to flowering, days to bolting, root yield per plant, total soluble solids and antioxidant-related traits such as DPPH, FRAP, ABTS, and total antioxidant activity, indicating substantial inherent diversity within the germplasm. Principal component analysis showed that the first two principal components explained 16.47% and 12.76% of total variation, respectively. PC1 was mainly associated with morphological, developmental and yield-related traits, whereas PC2 was largely associated with root yield, root weight% and whole-plant weight, indicating that genetic variability was distributed across multiple agronomic and biochemical traits. Hierarchical clustering grouped the genotypes into four distinct clusters; Cluster III, comprising Dunagiri NSP and Dunagiri Mandir, was highly divergent and superior for root yield and associated traits, while the remaining clusters represented variation for vegetative growth and biochemical attributes. Correlation analysis revealed positive associations of root yield with whole-plant weight, petiole length, petiole thickness, and root weight%, however a negative association with antioxidant traits, indicating a possible inverse association within the evaluated germplasm. Overall, the identified diverse and high-performing genotypes, including Dunagiri NSP, Dunagiri Mandir, IC 391,218, IC 255,478 and IC 391,330, may serve as useful genetic resources and breeding candidates for radish improvement.