Stability analysis of Iranian rice lines using additive main effects and multiplicative interaction (AMMI) model

Asessing genotype × environment interaction (GEI) and temporal stability is an essential step in crop breeding programs to identify high-performing lines. The aim of this study was to evaluate the temporal grain yield stability of twenty selected Iranian rice lines over three consecutive growing seasons (2020, 2021, and 2022) at a single location (Rice Research Institute of Iran, Rasht). The AMMI analysis of variance revealed significant effects of year (environment), genotype, and GEI. Mean grain yield comparisons using Tukey’s HSD test ( P < 0.05) confirmed significant variations among genotypes; specifically, line 9 exhibited the highest grain yield (5527.8 kg/ha), while lines 3 and 6 showed the lowest performance. Since selecting genotypes based solely on AMMI stability indices without considering average grain yield can lead to misleading results, simultaneous selection indices for yield and stability were used to identify stable, high-yielding genotypes more accurately. The results of all simultaneous selection indices identified line 9 as the most productive genotype among the 20 studied lines, while lines 1 and 8 were ranked as top candidates by all indices except ssiAMGE. In contrast, the AMMI1 biplot analysis designated lines 9, 8, 15, and 17 as promising entries. Finally, based on the combined results of simultaneous selection indices and AMMI biplot analysis, lines 9 and 8 are introduced as stable and high-yielding genotypes. Consequently, these two lines are recommended as highly promising candidates for further multi-location evaluations.