Growth, Water Relations, and Photosynthetic Activity Are Associated with Evaluating Salinity Stress Tolerance of Wheat Cultivars

Abeer Hamdy Elhakem,Wei Wu

doi:10.1155/2020/8882486

Abeer Hamdy Elhakem, Wei Wu

Open Access

https://doi.org/10.1155/2020/8882486

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Abstract

Salinity stress riskiness adversely affects the population by causing food and environmental issues. Moreover, the destructive impacts of salinization differ among various plant cultivars. In the present study, we evaluate the salt stress tolerance among three wheat cultivars based on growth criteria, leaf relative water content (LRWC), and abscisic acid (ABA) level by treating the plants with 0, 40, 80, or 160 mM NaCl. The results revealed that an increase in NaCl concentration caused a massive reduction in growth (shoot and root growth criteria and flag leaf area), photosynthetic pigments (chlorophyll a, chlorophyll b, carotenoids, and total pigments), and LRWC value, but a significant increase in the ABA content in flag leaf in all wheat cultivars. The wheat cultivars were otherwise exposed to anatomical characteristics and photosynthetic gas exchange investigations. NaCl toxicity induced a noticeable reduction in stomatal aperture area (SAA), stomatal conductance (Gs), transpiration rate (Tr), and leaf net photosynthetic rate (Pn). These impacts were remarkable with the 160 mM NaCl treatments for all evaluated parameters. Moreover, Sakha 69 revealed salinity tolerance greater than Giza168, and Sakha8 was the most salt-sensitive cultivar. Consequently, we recognized Sakha 69 as a salt-tolerant cultivar that may be used as parents in breeding programs for new cultivars with enhanced salt tolerance and for further genetic investigations to reveal the genetic strategies controlling the response of salinity stress in the wheat plant.

Highlights

Salinity stress is one of the major environmental issues restricting the crop growth and productivity in arid and semiarid regions. e land area influenced by salinization is continuously increasing day by day [1]
E results showed that the shoot’s fresh and dry weights were considerably decreased (p < 0.05) by the presence of salinity stress in relation to control values (Table 1). e decline was more obvious with a higher dose of salinity application (160 mM NaCl)
The maximum reduction in the shoot dry weights (DW) was noticed in Sakha8 (53%) followed by Giza168 (39%), and the minimum decrease was recorded in Sakha69 (32%) as compared to control

Summary

Introduction

Salinity stress is one of the major environmental issues restricting the crop growth and productivity in arid and semiarid regions. e land area influenced by salinization is continuously increasing day by day [1]. Salinity stress is one of the major environmental issues restricting the crop growth and productivity in arid and semiarid regions. Ere are various morphophysiological criteria such as growth parameters, plant-water relations, photosynthetic gas exchange properties, and pigment contents that are useful to detect the plant’s physiological status under saline conditions. Abscisic acid (ABA) is a significant phytohormone that can regulate growth and development of plants as well as the response of stresses. It plays an important role in the stomatal closure by regulating ion fluxes of guard cells. It was reported that there was a variation in ABA levels in the guard cells and roots after exposure to various treatments of NaCl stress [9]

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