Abstract

Environments in sub-Saharan Africa fluctuate considerably across sites and seasons. This suggests the importance of assessing genotype x environment interaction (GEI) in cultivar development. The objective of this study was to estimate the magnitude of GEI for rice grain yield and identify high yielding and stable rice genotypes. Fifty six genotypes including 45 F3 rice populations, their 10 parents and one check were evaluated in 7 x 8 alpha lattice design with two replications under three no drought and one random managed drought stress condition at reproductive growth stage at three sites in coast region of Kenya. The additive main effects and multiplicative interaction (AMMI) analysis and genotype plus genotype x environment interaction (GGE) biplot analysis were used to measure grain yield stability of the 45 F3 populations and their 10 parents. Ranking of the genotypes changed in each environment and three mega environments were identified revealing a crossover type of GEI. The genotypes G39 (Luyin 46 x IR74371-54-1-1) and G40 (NERICA-L-25 x IR55423-01) were the most stable high yielding genotypes. These were identified as candidates with general adaption for advancement to homozygozity simultaneously selecting within each population good performing pure lines for release in the region.

Key words: Additive main effects and multiplicative interaction (AMMI), genotype x environment interactions, genotype plus genotype x environment interaction (GGE) biplot, rice, yield stability.