Pattern Analysis of Genotype‐by‐Environment Interaction and Yield Stability in Promising Sugar Beet Hybrids by Additive Main Effects and Multiplicative Interaction and Genotype‐by‐Environment Biplot Models

Genotype‐by‐environment interaction (GEI) is a fundamental challenge in sugar beet breeding programs, complicating the selection ofsuperior cultivars with broad adaptation. The present study was conducted to investigate GEI patterns and identify stable, high‐yielding sugar beet hybrids for different regions of Iran. To this end, twenty sugar beet genotypes, comprising 15 promising hybrids and 5 check cultivars, were evaluated in a randomized complete block design with four replications across six regions (totaling 12 environments) during 2021 and 2022. Data were collected on root yield (RY), white sugar content (WSC), and white sugar yield (WSY), and were analyzed using the additive main effects and multiplicative interaction (AMMI) and genotype plus genotype‐by‐environment (GGE) biplot models. The combined analysis of variance revealed highly significant effects of environment, genotype, and GEI for the yield‐related traits. The AMMI model successfully captured a large portion of the GEI variance (over 80% for yield‐related traits) within the first few principal components (PCs). Based on the AMMI1 biplot analysis, hybrids SBSI‐152, SBSI‐153, and SBSI‐155 were identified as genotypes with a desirable combination of high yield and stability for WSY. Furthermore, the GGE biplot analysis facilitated specific cultivation recommendations by identifying ideal genotypes, including Novodoro, Modex, SBSI‐155, and SBSI‐153, and by grouping the trial environments into five distinct mega‐environments for WSY. Overall, the results indicated that the promising hybrids under study possess high potential for cultivation in various regions. The application of multivariate analyses was instrumental in identifying stable genotypes with general adaptation as well as superior genotypes for each mega‐environment, which can significantly enhance the efficiency of sugar beet breeding programs.