Evaluation of the yield stability of grain sorghum genotypes using AMMI analysis in different regions of Iran

Studying the interaction of genotype ×environment and identifying high-yielding and stable cultivars is very important for breeders. In this research, the yield stability and compatibility of ten grain sorghum genotypes were evaluated in seven regions of Iran, Karaj, Gorgan, Birjand, Isfahan, Shiraz, Hamadan and Zabol, during two years (2019-2020). The experiment was performed as randomized complete block design with three replications in all years and regions. The results of combined analysis of variance showed that the effect of location, year and genotype and all their interactions on grain yield significant at 1% probability level. The results of AMMI analysis also showed that the main effect of genotype, environment and interaction of genotype × environment as well as the first five main components of interaction on grain yield were significant (p≤0.01). In total, the cumulative share of the five main components was 93.61%. Genotypes 5 and 4 had the most positive and negative interactions, respectively. Although these genotypes had high grain yield, they were known as unstable genotypes. Genotypes 2 and 7 were selected as stable genotypes and are recommended to all regions based on the AMMI1 model. In this experiment, genotype number 7 with the lowest AMMI  stability value (ASV) was recognized as the most stable genotype and genotype number 1 with the highest ASV was recognized as the most unstable genotype. In terms of stability, genotype number 6 with the highest grain yield (7379 kg.ha-1) was ranked after genotypes 7 and 3. Genotype number 7 with the lowest value of interaction compared to the two axes (IPCA1 and IPCA2) was known as stable genotype and genotypes 2 and 9 had the highest values ​​of interaction. In terms of other stability indices such as MASV, SIPC, DZ, EV and ZA, genotypes 7 and 3 were determined as the most stable genotypes.