Multi-trait evaluation and index-based selection of advanced F10 quinoa (Chenopodium quinoa Willd.) lines under Peruvian highland conditions

ABSTRACT Quinoa (Chenopodium quinoa Willd.) is an Andean grain crop valued for its high nutritional quality and broad environmental adaptability. Increasing climatic variability in the Peruvian highlands threatens quinoa productivity, highlighting the need for cultivars that combine high yield potential with early maturity. This study evaluated nine advanced F₁₀ lines, five parental varieties, and two commercial control cultivars during the 2019-2020 growing season at Potojani Farm, Puno, Peru. A randomized complete block design with four replicates was used, and linear mixed-effects models were fitted to obtain best linear unbiased estimates (BLUEs) and predictors (BLUPs). Broad-sense heritability was estimated using the Cullis method. Significant genotypic differences were detected for yield, phenological, and architectural traits (P < 0.05). Thousand-kernel weight and days to physiological maturity exhibited high heritability (H² = 0.98 and 0.88, respectively), whereas seed yield per plant showed moderate heritability (H² = 0.68). Correlation and principal component analyses revealed partial independence between phenological and architectural traits and yield-related traits, indicating that productivity can be improved without extending the duration of vegetative growth. A weight-free Elston selection index integrating seed yield, maturity, plant height, stem diameter, and thousand-kernel weight identified Salcedo INIA × Pandela Rosada 171 as the superior multi-trait genotype, followed by SAL × Negra Collana 30 and SAL × COL 37. These findings confirm the presence of exploitable genetic variability and demonstrate measurable genetic progress toward the development of genotypes with balanced yield performance and phenological adaptation under highland conditions.