Genetic parameters and selection criteria in quinoa

Quinoa (Chenopodium quinoa Willd.) is a crop with high nutritional and agronomic potential, adapted to environmental stress conditions. It is grown on a small scale in Mexico, and currently improved varieties are not available. In order to establish the basis to guide genetic improvement in Mexico, the objective was to determine the genetic variability, heritability and interrelationships of yield and its components in 16 quinoa genotypes, in a randomized complete block design, in six environments in the central high valleys of Mexico. The proportion of participation of the sources of variation genetic, environmental, and genotype x environment interaction was determined; as well as heritability, response to selection, and phenotypic correlations among morphological characters, yield and its components. Out of 15 variables evaluated, the genetic effects on thousand-grains weight and grain filling period were the most important; whereas for plant height at flowering, harvest index, and stem diameter, environmental effects were the most relevant. The genotype x environment interaction is not greater than 20 % for the 15 variables evaluated. The highest values for additive variance, heritability, and response to selection were for grains per square meter, yield, thousand-grains weight, grain filling period, and panicle emergence. The variables stem diameter, plant height at maturity, grains per square meter, yield per day, grain filling period, and panicle emergence were the most correlated with yield. Therefore, they can be used as indirect yield selection criteria in breeding programs to obtain materials with better agronomic characteristics. Based on the genetic parameters obtained and the association of the variables with yield, grains per square meter, yield per day and plant height at maturity are the most appropriate traits for indirect selection for yield.