Morphological characterisation, genetic variability and grain iron-zinc profiling of indigenous rice (Oryza sativa L.) landraces

Traditional rice (Oryza sativa L.) landraces possess extensive genetic diversity and are valuable sources of alleles for improving yield, grain quality and nutrition. The present study was conducted at College Farm, Agricultural College, Aswaraopet, during kharif 2024 using 66 indigenous landraces and four standard checks (BPT 5204, Chittimutyalu, DRR Dhan 45 and Zincorice) in an augmented block design. Wide phenotypic diversity was observed for qualitative traits, including culm growth habit, flag leaf orientation, stem anthocyanin pigmentation, awn distribution, leaf colour intensity and kernel colour. Analysis of variance (ANOVA) revealed significant differences for all 14 quantitative traits, confirming substantial genetic variability. Grain yield per plant (GYP) ranged from 12.09 to 34.20 g, plant height from 58.37 to 142.42 cm and number of filled grains per panicle (NFP) from 38 to 142. High genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) were observed for GYP, grain iron (Fe) concentration, panicles per plant, NFP and kernel breadth (KB). Most traits exhibited high heritability coupled with high genetic advance as a percentage of mean, indicating predominant additive gene action and effectiveness of direct selection. Grain Fe and zinc (Zn) concentrations ranged from 3.87–15.30 and 10.63–25.48 ppm, respectively. DRR Dhan 45 recorded the highest Fe concentration, while Kumargorla had the highest Zn concentration. Siddhasanna combined higher Zn concentration (21 ppm) with high GYP (30.54 g). These landraces represent promising donor materials for rice biofortification and development of nutritionally enriched, high-yielding cultivars.