Prashansa Pandey, Saurabh Joshi Newar, Bishwash Dhungel, Raju Kharel
Milling and aromatic quality are two of the most economically important post-harvest attributes that determine the market value and consumer acceptance of rice (Oryza sativa L.). This study evaluated six milling quality traits and grain aroma in 30 rice landraces along with 3 released check varieties of Nepal. Milling quality was assessed in a completely randomized design (CRD) with three replications following the IRRI Rice Knowledge Bank protocol, while grain aroma was scored using the standard 1.7% KOH sensory method on a 1-4 intensity scale by a panel of evaluators. Analysis of variance revealed significant genotypic differences for all studied milling quality traits. Head rice recovery, the most economically valuable milling trait, ranged from 50.07% (Ramkumar-3) to 75.05% (NGRC02829), with NGRC02829 emerging as the best milling-quality genotype. The KOH aroma test classified the 33 genotypes into four groups: 8 non-aromatic, 21 slightly aromatic, 3 moderately aromatic, and 1 strongly aromatic (Kalo Nuniya, mean score 3.50 ± 0.84), a genotype independently documented as an aromatic Nepalese landrace. A Kruskal-Wallis test confirmed significant genotypic variation in aroma intensity (H = 66.84, df = 32, p < 0.001), corroborated by a complementary one-way ANOVA (F = 3.10, p < 0.001), although inter-panelist agreement was low (Fleiss' κ = 0.05), reflecting the well-documented subjectivity of sensory-based aroma scoring. Hierarchical cluster analysis based on the combined milling and aroma trait profile grouped the genotypes into four clusters, separating a superior-milling cluster (headed by NGRC02829) from a poor-milling cluster, and showed that the strongly aromatic landrace Kalo Nuniya did not belong to the best-milling group. Overall, the study identifies landraces with superior milling recovery and distinct aroma expression that represent valuable breeding material for improving the grain quality of Nepalese rice.