Evaluation of sugar beet (Beta vulgaris L.) cultivars for some biochemical and agronomic traits under drought stress

This experiment aimed to evaluate quantitative and qualitative characteristics, tolerance to water deficit, and stability of white sugar in sugar beet cultivars. The experimental design was a split plot based on a randomized complete block design with three replications, where the irrigation levels (normal and water shortage) were assigned to the main plots and 18 sugar beet cultivars were assigned to the subplots. The result revealed that Palma achieved the maximum root and white sugar yield under normal and water deficit; furthermore, the highest indices of YP, YS, MP, STI, HM, YI, DI, REI and MRP belonged to the Palma cultivar. The results of the AMMI analysis based on white sugar yield showed that the additive effects of genotype and environment and the multiplicative effect of G×E accounted for 75.52, 17.05 and 6.76 % of the total data variance. Based on AMMI stability value, the Delta, Pars, Paya and Novodoro cultivars were recognized as stable varieties. Also, the first 2 significant components of the interaction effect (G×E) accounted for 99.12 % of interaction effects variation. Based on the biplot results of the first 2 significant components against white sugar yield, Azare and Merak were the appropriate cultivars. Finally, Based on the multi-trait stability index, Azara, Novodoro and Merak cultivars were selected as stable genotypes. In 2 years and 2 conditions, the Palma cultivar was identified as a cultivar with high yield and drought tolerance and low stability and the Merak cultivar was identified as a cultivar with white sugar yield and acceptable stability.