GENOTYPE x ENVIRONMENT INTERACTION OF SOYBEAN GENOTYPES IN ECUADOR

Soybean [Glycine max (L) Merrill.] in Ecuador is one of the main short-cycle crops in the coastal region, and it is an important economic component for the country. Seven soybean genotypes developed at the University of Guayaquil, Ecuador, and a commercial variety were studied to know their adaptability and phenotypic stability, grain productivity and resistance to Asian rust (Phakopsora pachyrhizi). In seasons 2015, 2016 and 2017, eight trials were planted in representative environments at the province of Los Rios, Ecuador under a randomized-complete-blocks design with four replications. Agronomic characteristics of the plants and yield and its components were evaluated and analyzed by analysis of variance and multiple range comparisons by Tukey tests (P <= 0.05). Additionally, the association between yield and its components was studied through Pearson correlations and linear regression. To evaluate genetic stability, the model of additive main effects and multiplicative interaction (AMMI model) was used. The So ITAV 7 line had the highest grain yield and was the most stable. Soybean genotypes established in the Vinces locality displayed the lowest severity of Asian rust.