Evaluation of Some Sugar Beet Genotypes Under Drought Stress Based on Selection Indices

Abstract

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

Salinity Tolerant Indices Based on Yield Performance of Some Sugar Beet Varieties as Treated by Potassium Silicate to Mitigate Saline Soil Stress

“…SSI, YSI, and STI were correlated with yield under stress conditions, compared with indices (decrease percentage), suggesting that these constructions are suitable for screening salinity-tolerant and high-yielding treatments under saline soil conditions. These results are in harmony with those obtained by Farshadfar et al (2012), Okasha and Mubarak (2018) who indicated that varieties with high STI, and YSI values were suitable for cultivation under non-stress environments also, indicate that STI and YSI, indices were more effective in identifying highyielding genotypes under stress as well as nonstress conditions.…”

“…Meanwhile, the most sensitive varieties "Melodia" and "Narmar" in the first and second seasons, respectively, had a salinity susceptibility index (SSI) more than unity. The positive effect of indices on selecting the stresstolerant sugar beet varieties was investigated by Wenbo et al (2023) and Okasha and Mubarak (2018). They found that the stress tolerance capacity of sugar beet germplasms could not be evaluated by using a single indicator, as the evaluation results would be inaccurate.…”

Evaluation of some Alfalfa (Medicago sativa L.) varieties under the drip irrigation system at North Sinai governorate, Egypt

“…This suggests that these indices were successful in identifying genotypes that produced high yields in both drought stress and non-stress conditions. The control-50% analysis using principal component analysis identified genotype Bts 1237 and Temar as the most stable high yielding genotypes in both environments (Okasha and Mubarak, 2018).…”

Drought resistance evaluation of sugar beet germplasms by response of phenotypic indicators

“…It usually lasts for 2 y in cropland, which is complex and low throughput. 11 The drought resistance coefficient is more effective for selecting better genotypes with respect to tolerant, because a single index or comprehensive analysis of different traits has shortcomings in identifying drought resistance. 12 …”