Response in Physiological Traits and Antioxidant Capacity of Two Cotton Cultivars under Water Limitations

Abstract

Deficit irrigation water (DW) is one of the main stress factors that negatively affect cotton cultivation. Hence, the identification of cotton cultivars tolerant to DW and sandy soil conditions is particularly needed. Understanding the response of cultivars to DW is essential for estimating water needs. Besides, by understanding the physiological and antioxidant status, reflecting distinct growth, yield, and fiber quality traits under DW, the cultivar tolerant to DW can be identified in the early stage of plant growth. Therefore, two cotton cultivars (Giza 86 and Giza 92, selected for their suitability to the climatic conditions of the study area) were evaluated in this study under two DW regimes (80% or 60% of crop evapotranspiration; ETc) vs. complete irrigation water (CW; 100% of ETc as a control). These regimes amounted to 1228 or 922 vs. 1536 mm season−1, respectively, for field trials conducted during the 2019 and 2020 summer seasons. DW (80% or 60% of ETc) significantly decreased relative water content, membrane stability index, chlorophyll content, plant height, yield components, and fiber quality traits. Otherwise, phenolic compounds, proline contents, as well as antioxidant enzyme activities increased in concomitance with an increase in electrolyte leakage and malondialdehyde content. The harmful effects of the higher DW (60% of ETc) were more pronounced in both cultivars. However, compared to Giza 86, Giza 92 showed higher performance under both CW and DW regimes, accounting for higher values for all studied traits in the blooming stage. The correlation coefficient showed that most of the physiological traits and antioxidants under study were effective criteria in identifying a high-yielding cultivar under DW in the cotton blooming stage and therefore can be used to select the cotton cultivar more suitable for the conditions of the study area. Biplot analysis was used to study the relationship between DW and all evaluated traits, as it was found that the most prominent traits were elongation (%) with Giza 92 + 100% ETc, yellowness degree with Giza 86 + 100% ETc, and SOD with Giza 92 + 60% ETc.

Application of 2,4-Epibrassinolide Improves Drought Tolerance in Tobacco through Physiological and Biochemical Mechanisms

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Response of cotton genotypes to water-deficit stress using drought tolerance indices and principal component analysis

“…Ayele et al (2020),Yehia (2020), andEid et al (2022) observed the same trend when compared to water-de cit stress conditions; cotton genotypes in normal irrigation conditions showed higher seed cotton yield, which ranged from 11.12% by G3 to 28.03% by G7, suggesting genetic variability in eleven studied genotypes for drought tolerance. Also,Grzesiak et al (2019) andSun et al (…”

“…Cotton genotypes tolerant to drought stress and sandy soil conditions are especially needed in areas where drought is a major stress factor affecting cotton agriculture (Eid et al 2022). Results of combined ANOVA exhibited statistically signi cant differences (p ≤ 0.05 or 0.01) among genotypes (G), years (Y), and GY interaction for seed cotton yield under normal irrigation and water-de cit stress conditions.…”

Drought Stress Alters Photosynthetic and Carbohydrate-related Proteins in Leaves of Banana

“…This might be due to the elevated CAT and POD activities to decompose H 2 O 2 to oxygen and water molecules. Enhanced activity of antioxidant enzymes in response to drought stress was also reported in soybean (Moloi and Merwe 2021), cotton(Eid et al 2022), and silymarin (ElSayed et al 2019). Alterations in ribosomal proteins have also been reported in drought-stressed foxtail millet(Pan et al 2018) and salt-stressed cucumber(Du et al 2010).…”