The adaptability of promising maize hybrids to environmental changes in different regions of Iran

The sustainability of agricultural systems plays a key role in adapting to climate change. There is ample evidence that biodiversity can increase the stability of ecosystem processes by changing environmental conditions. Therefore, the effectiveness of breeding programs requires a correct understanding of the reaction of breeding cultivars to environments with different climatic and soil conditions. Therefore, this study was conducted to assess the response of some new maize hybrids to divergent environmental conditions and determine their grain yield stability.

This study was conducted with 16 maize hybrids using a randomized complete block design with three replications in six locations, during the 2017 cropping season. Considering significant differences for hybrid × environment (GxE) interaction, stability analyses were performed using AMMI and GGE-biplot methods to determine stable and high-yielding hybrids.

The results of the AMMI model showed that only the first two principal components of AMMI (AMMI1and AMMI2) were significant and described 68.53% of the variance of G×E interaction. Based on the results of statistics of the AMMI model (ASV and SPCA1), hybrids No. 16 (SC704) and 1 (KLM77002/3-1-1-1-1-1-1-3 × K18) were recognized as the most stable hybrids. Stability analysis by GGE biplot procedure explained 71.5% of grain yield variation due to two components of GGE. In addition, hybrids No. 16 and 1 were identified as superior and stable hybrids by the GGE biplot graphical method.

Generally, results of grain yield and stability analyses showed that hybrids No. 16 and 1 with 12.76 and 11.72 t/ha yields, respectively, were better than other hybrids across environments for yield and stability with wide adaptation and thus can be cultivated in Iran. Also, biplot analysis of correlation among environments revealed that Kermanshah, Esfahan, and Shiraz, as well as and Moghan and Miyandoab were closer and similar in ranking, grouping, and assessing stability. Also, Kerman and Karaj regions were less similar to other regions in terms of hybrids discrimination. Considering the high discriminate power of hybrids in Shiraz, Miyandoab, Kerman, and Karaj environments, and in order to decrease the costs, it is recommended to conduct future trials in the aforementioned environments.