Abstract

This study aimed to assess the potential of elite rice lines to perform consistently and provide a high yield in several testing environments in Tanzania. A total of eleven rice genotypes were assessed for their yield performance and stability during two consecutive cropping seasons at three different environments. The assessment of grain yield stability was conducted using the Additive Main effect and Multiplicative Interaction (AMMI) and genotype by environment (GGE) biplot statistical models. These models are widely used to identify superior rice cultivars and ideal testing environments. The combined analysis of variance revealed statistically significant (p < 0.05) effects of genotypes, environments, and their interaction on grain yield. Genotypic performance was greatly affected by seasonal variability. The AMMI analysis revealed that the contributions of genetic (G), environmental (E), and genotype-environment interaction (GE) impacts to the overall variation in grain yield were 11.73%, 31.92%, and 1.90%, respectively. The study highlights the considerable challenge posed by genotype-by-environment interactions in crop breeding and the need to comprehend the genetic pathways that underlie environmental adaptability. It is essential to identify rice cultivars that are both stable and adaptable, and to determine highly discriminative testing conditions, to generate elite rice cultivars in Tanzania. The research findings offer useful insights for rice breeding programs to improve the selection of superior genotypes and optimize testing environments to maximize grain yield.

Key words: Rice genotypes, genotype x environment interaction, yield stability.