AMMI analysis of genotype x environment interaction and stability of cassava genotypes for yield and quality traits
Abstract
Cassava (Manihot esculenta Crantz) productivity is strongly influenced by genotype × environment interaction (G × E), which complicates the identification of superior and stable genotypes for cultivation across diverse environments. This study evaluated fifteen cassava accessions across three environments using combined analysis of variance (ANOVA) and the Additive Main Effects and Multiplicative Interaction (AMMI) model to determine the effects of genotype, environment, and their interaction on agronomic and quality traits. Traits assessed included root number, shoot weight, total root weight, fresh root yield (FRY), dry yield, dry matter content (DMC), starch content, and harvest index (HI). Combined ANOVA revealed significant genotypic variation for root number, shoot weight, total root weight, DMC, starch content, and HI, indicating the presence of exploitable genetic variability among accessions. Environmental effects significantly influenced shoot weight, total root weight, FRY, DMC, starch content, and HI, demonstrating the importance of environmental conditions in trait expression. Genotype × environment interaction was significant for FRY and DMC, suggesting differential genotype responses across environments, but was non-significant for root number, shoot weight, total root weight, starch content, and HI, indicating relatively stable performance for these traits. AMMI analysis identified F22P001 as the highest-yielding genotype (19.62 t ha⁻¹), although it exhibited low stability (ASV = 1.81). Conversely, F135P001 and F9P0002 were the most stable genotypes (ASV = 0.54). TMEB7 combined desirable yield performance (11.47 t ha⁻¹) with good stability (ASV = 0.65), making it a promising genotype for broad adaptation. The findings highlight the value of integrating yield, quality, and stability assessments to enhance cassava breeding andcultivar recommendation across diverse agroecological environments.