Genotype by environment interaction and stability analysis for new sugar beet (Beta vulgaris l.) genotypes under natural rhizomania contamination conditions

The aim of this research was to evaluate the stability of 11 hybrid sugar beet varieties and two resistant control cultivars, Denzel and Melindia, in the presence of natural Rhizomania conditions. A two-year experiment was conducted at five agricultural stations in Iran: Karaj, Mashhad, Miandoab, Zarqan, and Hamedan, utilizing a randomized complete block design with four replications. The results showed no significant differences in sugar content (SC), white sugar content (WSC), and white sugar yield (WSY) between the hybrids F-21374 and F-21375, and the resistant cultivar Melindia, across all locations. The Additive Main effects and Multiplicative Interaction (AMMI) stability value (ASV) index revealed that the Denzel cultivar demonstrated the greatest stability for SC and WSC, while hybrids 21372, F-21374, and F-21376 were the most stable for WSY. Additionally, F-21376, F-21375, and F-21374 were found to have high and steady values for all principal components (PCs) involved in genotype ​× ​environment interaction, such as Weighted Average of Absolute Scores for Stability and Mean Performance (WAASBY), Weighted Average of Absolute Scores (WAAS), and the best linear unbiased prediction (BLUP). Further analysis using the Multi-Trait Stability Index (MTSI) indicated F-21376 and F-21370 hybrids as the most promising in terms of cultivar stability for all the examined quantitative and qualitative traits. Lastly, based on the Multi-Trait Genotype-Ideotype Distance Index (MGIDI), hybrids F-21374 and F-21375, along with resistant Melindia, were identified as being closest to the ideal genotype for all assessed traits. Therefore, it can be concluded that F-21376, F-21375, and F-21374 possess strong quantitative and qualitative traits and resistance to rhizomania and are potential candidates for future sugar beet varieties.