Studying the Effect of Genotype-Environment Interaction on the Quantitative and Qualitative production Potential of Different Sugar Beet Cultivars (Beta vulgaris L.)

The yield and quality of sugar in this plant, like other plants, are strongly influenced by environmental factors, and high modifications occur in its quantitative and qualitative performance. Therefore, the present research was designated and implemented to study the effect of genotype-environment interaction on the quantitative and qualitative production potential of sugar beet cultivars and also determine their adaptability to a wide range of environments with different conditions.

Seven cultivars of sugar beet, consisting of four domestic and three foreign cultivars formed the genetic material of the present study. The plant materials under investigation were cultivated in the randomized complete block design with four replications in four regions of Borujerd, Piranshahr, Jovein, and Shirvan in 2021. After harvesting and estimating root yield, sugar content, white sugar yield, and extraction coefficient of sugar for each of the experimental cultivars, analysis of the stability of root yield and white sugar yield were done by using the additive main effect and multiplicative interaction model and simultaneous analysis of the stability of four measured characteristics with a multi-trait stability index.

The additive effects analysis results of AMMI's model showed that genotype, environment, and genotype-environment interaction were significant at the 1% probability level. Analyzing the multiplicative effect of AMMI's model into principal components showed that in both studied traits, only the first two components of the interaction were significant at the 1% probability level. According to the biplot of the mean yield against the weighted average of absolute scores of the principal components, the Dena in terms of root yield and Dena and Sina in terms of white sugar yield was known as stable cultivars with suitable yield. In the biplot of the first and second principal components of the genotype-environment interaction, the Dena in terms of root yield and Dena, Ekbatan, and Sina in terms of white sugar yield was recognized as cultivars with suitable general adaptability. The studied areas were divided into three mega-environments in terms of each root yield and white sugar yield, so Jovein and Shirvan were identified as the first mega-environment, Borujerd as the second mega-environment, and Piranshahr as the third mega-environment. Based on the results of the multi-trait stability index, the Perfekta was the most ideal cultivar at the same time in terms of all four traits of root yield, white sugar yield, sugar content, and extraction coefficient of sugar, and after that, Flores and Sina were the ideal cultivars.

According to the obtained results, it can be concluded that the environmental conditions and their interaction with the genotype play a significant role in influencing the phenotypic expression of traits in different sugar beet genotypes and cause yield fluctuations from one environment to another. Therefore, it is necessary to be more careful when releasing genotypes to introduce genotypes that are adaptable to the conditions of the target environment and produce suitable products.