IMPACT OF SALT STRESS ON GROWTH PARAMETERS, CHLOROPHYLL CONTENT, AND OXIDATIVE DAMAGE IN DIVERSE WHEAT CULTIVARS AT SEEDLING STAGE - Muhammad Sajawal Ghafoor; Aroob Hassan; Rabia Naz; Asia Nosheen; Humaira Yasmin; Muhammad Sajjad; Rumana Keyani (Journal of Animal and Plant Sciences, 2026)
Plant growth and productivity are being adversely affected by several biotic and abiotic stresses that collectively lead to drastic yield losses globally. Increased soil salinization and climate change are posing serious threats to sustainable production of all the crops including wheat. This study explored the agronomic, physiological, and biochemical responses of fourteen diverse Pakistani wheat varieties to salt stress. In this study, plants were exposed to 150 mM saline conditions for ten days, after 30 days of growth under normal conditions. Key growth indicators, photosynthetic pigments and antioxidant parameters were evaluated to assess the genotypic variation in stress tolerance. The experiment was conducted in completely randomized design (CRD) with factorial arrangement, comprising fourteen wheat varieties and two salinity treatments (control and 150 mM NaCl), with three replications. Among growth indicators, highest variation was observed in their root length, with Chakwal-86, Galaxy-2013, and Akbar-2019 exhibiting the higher tolerance and less affected root length, while highest reduction was observed in Sehar 2006, Chakwal 97, Suleman 96, and Inqilab 91. Photosynthetic pigments were affected more in Pakistan 81, Auqab 2000, Chakwal 97, Suleman 96, and Ujala 2016 with up to 38% reduction in total chlorophyll contents while Chakwal 86, Akbar 2019, and Pakistan 2013 showed less reduction under stress conditions with minimum reduction of up to 10%. Chakwal 86, Akbar 2019 and Galaxy 2013 showed higher increase in the activity of antioxidant enzymes under salinity with minimal lipid peroxidation while Pakistan-81, Inqilab-91, Sehar-2000, and Ujala 2016 showed higher oxidative damage under stress. The increase in activity of antioxidant enzymes varied between 6% to 48% in case of Catalase, 7%-10% in case of superoxide dismutase (SOD), 2%-29% in ascorbate peroxidase (APX) and between 11% to 45% in case of peroxidase (POD). Higher malondialdehyde (MDA) contents of up to 62% were observed in Pakistan 81, Margalla 99 under salinity, while less increase in MDA of up to 28% was observed in Chakwal 86, Galaxy 2013, Pakistan 2013. Overall, it was found that Pakistan 81, Margalla 99 and Suleman 96 were not able to perform well under salinity stress, while Chakwal 86, Galaxy 2013 and Pakistan 2013 were better able to deal with stress conditions. It is suggested that these tolerant genotypes can serve as valuable genetic resources for breeding programs with an aim to improve wheat performance under saline conditions.
Keywords: journal article; salt stress; chlorophyll; malondialdehyde; antioxidant activities; wheat