Univrsity of Tehran Press Iranian Journal of Field Crop Science 2008-4811 53 3 2022 09 23 Evaluation of physiological indices of sugar beet (Beta vulgaris L.) genotypes under water deficit stress Evaluation of physiological indices of sugar beet (Beta vulgaris L.) genotypes under water deficit stress 77 91 89808 10.22059/ijfcs.2021.326319.654838 FA Milad Ghasemi Ph.D. Student Dept. Of Plant Breeding and Biotechnology, Faculty of Agriculture, University of Tabriz, Tabriz, Iran. Mahmoud Toorchi Dept. of Plant Breeding & Biotechnology, Faculty of Agriculture, University of Tabriz, Tabriz, Iran Saeid Aharizad Department of Plant Breeding and Biotechnology, University of Tabriz, Tabriz Abdolmajid Khorshid Agriculture and Natural Resources Research Center, Agricultural Research, Education and Extension Organization (AREOO), Urmia, Iran Journal Article 2021 07 04 Due to arid and semi-arid climates, identification of water deficit stress tolerant genotypes is really important in Iran. To select tolerant genotypes, it is necessary to use important and practical indicators. In this regard, this study was conducted to studying the effect of water deficit stress on 27 sugar beet genotypes in a split plots based on randomized complete block design 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 planted in the PVC tubes. Studied traits included transpirational cooling before and after irrigation, 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, genotype, and irrigation × genotype interaction effects were significant for all studied traits at 1% of probability level. 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, Full sib S1- 10- 8001 genotype was identified as the tolerant genotype. Due to arid and semi-arid climates, identification of water deficit stress tolerant genotypes is really important in Iran. To select tolerant genotypes, it is necessary to use important and practical indicators. In this regard, this study was conducted to studying the effect of water deficit stress on 27 sugar beet genotypes in a split plots based on randomized complete block design 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 planted in the PVC tubes. Studied traits included transpirational cooling before and after irrigation, 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, genotype, and irrigation × genotype interaction effects were significant for all studied traits at 1% of probability level. 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, Full sib S1- 10- 8001 genotype was identified as the tolerant genotype. https://ijfcs.ut.ac.ir/article_89808_9e134b6f72491318ba05ae5d0b40b90b.pdf