Genotype by environment interaction in sesame germplasm in Mexico

Abstract

In Mexico, sesame (Sesamum indicum L.) is cultivated in rainfed environments with high temperatures and erratic precipitation. In these environments, there is low productivity due to the low availability of improved varieties; however, there is genetic diversity that can be used in programs for crop improvement. The objectives were to evaluate the grain yield per hectare (GY), variables associated with it, and the genotype × environment interaction (G × EI) in 50 sesame genotypes in four environments; these environments were integrated by Iguala and Zicapa in the spring–summer cycles 2021 and 2022 in Guerrero, Mexico; an alpha lattice design with three repetitions was used. The following analyses were conducted: combined analysis of variance, multivariate additive main effects and multiplicative interaction (AMMI), stability analysis, and Biplot G + G × EI. The combined analysis detected significant differences (p ≤ 0.01) for environment, genotype, and G × EI in every variable. The AMMI analysis showed greater variation in environment; the genotype component indicated 58.3% of variation of the GY and 24.8% of the G × EI. The coefficient of regression varied from 0.03 to 2.45, and the regression deviation was 0.03–0.26, with this indicating that the genotype had different responses to the environments. The Biplot G + G × EI with two components explained 80.75% of the variation in GY. The models and parameters used indicated that the Los_Hornos genotype (792.31 kg·ha⁻¹) presented a better stability and GY classification, higher than the general average (569.9 kg·ha⁻¹) and the improved control Calentana (591.85 kg·ha⁻¹). Therefore, this genotype can have a significant impact on the genetic gain of GY for future sesame improvement programs.