Genotype by environment interaction across water regimes in relation to cropping season response of quinoa (Chenopodium quinoa)

Abstract

Genotype × environment (GxE) interaction effects are one of the major challenges in identifyingcultivars with stable performance across agri-environments. In this study we analysedGE interactions to identify quinoa (Chenopodium quinoa) cultivars with high and stableyields under different soil moisture regimes, representing control conditions, waterloggingand drought. Waterlogging and drought treatments were artificially induced using normoxia,a combination of hypoxia-normoxia, and 10% PEG (Polyethylene glycol) under hydroponicgrowth conditions, respectively. Both waterlogging and drought conditions significantlyreduced the plant height (PH), number of leaves (NoL) and number of branches (NoB),stem diameter (SD), leaf area (LA) and dry weight (DW) of quinoa genotypes. The genotype,water regime, and genotype by water regime effects all significantly affected the measuredquinoa traits. Based on the additive main effects and multiplicative interaction (AMMI) modelfor DW, the genotypes G18, Puno, Q4, 2-Want, Puno, Real1 x Ruy937 and Titicaca werefound to exhibit tolerance and were stable across water regimes. A second-stage evaluationwas conducted to test genotype × environment interaction effects in crop production field trials,selecting two contrasting seasons based on soil moisture conditions involving a diverseset of genotypes (58 varieties in total). Our results demonstrate significant variations in bothgrowth and yield among the quinoa genotypes across the cropping seasons. The GGE analysisfor grain yield indicate that field conditions matched to G × E under hydroponic experimentalconditions and the cultivars G18, Q1, Q4, NL-3, G28, 42-Test, Atlas and 59-ALCwere classified within a range of high productivity. Our findings provide a basis for understandingthe mechanisms of wide adaptation, while identifying germplasm that enhancesthe water stress tolerance of quinoa cultivars at early growth stages.