Evaluation of physiological indices of sugar beet (Beta Vulgaris L.) genotypes under water deficit stress

Due to arid and semi-arid climates, identification of tolerant genotypes to water deficit stress is of great importance in Iran. To select of tolerant genotypes, it is necessary to use important and practical indicators. In this regard, this study was conducted by studying the effect of water deficit stress on 27 sugar beet genotypes in split plots based on randomized complete blocks in three replications at the University of Tabriz in 2019. The main factor included two irrigation levels (optimal and water deficit), and the sub-factor included 27 sugar beet genotypes. In this experiment, sugar beet seeds were implanted in PVC tubes. Studied traits include transpirational cooling before and after irrigation, the relative water loss (RWL), relative water content (RWC), Root weight (RW), electrolyte leakage (EL), initial fluorescence (F0), maximum fluorescence (Fm), and quantum yield of photosystem II. Based on the analysis of variance, irrigation effect, genotype, and irrigation interaction × genotype were significant for all studied traits at the level of 1% probability. Also, the relative lost water, relative water content, maximum fluorescence, and quantum yield of photosystem II were significantly reduced due to water deficit stress. In terms of Transpirational cooling indices after irrigation, relative water content, Root weight, electrolyte leakage, initial fluorescence, and quantum yield of photosystem II, genotype of Full sib S1- 10- 8001 was identified as tolerant genotype.