Evaluation of Some Sugar Beet Genotypes Under Drought Stress Based On Selection Indices - Evaluation of Some Sugar Beet Genotypes Under Drought Stress Based On Selection Indices - Open Access Pub

This study was conducted to determine drought tolerant indices of some sugar beet genotypes under water stress and non-stress conditions. Nine sugar beet (Beta Vulgaris L.) genotypes were tested in a Split-plot experiment based on a randomized complete block design in three replications under three levels of water stress 100%, 75% and 50% from plant requirements at the experimental farm Faculty of Agriculture, Suez Canal University, Ismailia, Egypt during 2015/ 2016 and 2016 / 2017 seasons. Twelve drought tolerance indices were used in this study, stress sensitivity index (SSI), stress tolerance (TOL), mean productivity (MP), geometric mean (GMP), harmonic mean (HM),yield stability index (YSI), yield index (YI), stress tolerance index (STI), sensitivity drought index (SDI), relative drought index (RDI), drought response index (DI) and stress susceptibility percentage index (SSPI). GMP, MP and STI were more informative towards classification of better or superior genotypes with respect to tolerant and sensitive groups. The results showed that the genotypes with high STI, GMP and MP values were suitable for cultivation under drought stress and non-stress environments. Both Yp and Ys of root yield in the control-50% analysis had significantly positive correlated (P value<0.05) with MP, GMP, YI, HM and DI, This indicates that these indices were more effective in identifying high yielding genotypes under drought stress as well as non-stress conditions.Principal components analysis showed that the first two components in the control-50% analysis, genotype Bts 1237 and Temar were identified as the most stable high yielding genotypes in both environments DOI10.14302/issn.2639-3166.jar-18-2083 Drought is a common phenomenon in warm and dry environment, and selection for drought tolerance is one way to reduce the effects of water stress on crop yield 1. The decrease in annual precipitation that is predicted for Northern African countries in the 21st century will exacerbate expected rising temperatures effects, particularly in semiarid and arid regions, that must be rely on irrigation for crop growth 2. Drought stress tolerance is a complex trait that is obstructed by low heritability and deficiency of successful selection approaches 3, 4. In many cases, increased irrigation inputs are not available option because of the water resources are less available or that they are too expensive. In a world limited by supplies of freshwater, the trend is towards great restrictions on agricultural water use 5. With increasing world's population, the situation is getting