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العنوان
ALLEVATING THE IMPACT OF SALINTY STRESS ON MAIZE PLANTS USING SOME ANTIOXIDANTS /
المؤلف
Dekhil, Maha Abdel Fattah Ibrahim.
هيئة الاعداد
باحث / مها عبد الفتاح إبراهيم دخيل
مشرف / سناء عبد الرحمن زغلول
مشرف / هاني صابر سعودي
مشرف / محمد فرج محمد
تاريخ النشر
2021.
عدد الصفحات
108 p. :
اللغة
الإنجليزية
الدرجة
ماجستير
التخصص
الهندسة الزراعية وعلوم المحاصيل
تاريخ الإجازة
1/1/2021
مكان الإجازة
جامعة عين شمس - معهد البيئة - العلوم الزراعية البيئية
الفهرس
Only 14 pages are availabe for public view

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Abstract

The current investigation aimed to study the effect of foliar application of α-tocopherol (Toc, 25 and 50 ppm.) and selenium, Na2SeO4,(Se, 2.5 and 5 µM) on maize plants irrigated by three different concentrations (0, 50 and 100 mM) of saline water as NaCl.
To investigate each one of the abovementioned treatments, two pot experiments were carried out at the Experimental Farm, Faculty of Agriculture, Ain Shams University, Shoubra El-Kheima, Kalubia Governorate, Egypt during the summer growing seasons of 2017 and 2018.
Accordingly, the results of present work can be summarized as following:
1. Growth parameters
1. Exposing maize plants to salt stress dramatically decreased and significant (P≤0.05) adversely negatively affected all studied growth parameters, photosynthetic pigmentsand grain yield of maize and its attributes compared to the unstressed plants in both seasons.
2. Foliar application of 25 ppm α-tocopherol achieved the highest significant valuesof plant height compared to the other treatments in both seasons.Moreover, the treatment of 2.5 µM Na2SeO4 resulted in the highest significant values in leaf area, leaves fresh weight, stem fresh weight, total shoot fresh weight, stem dry weight and total shoot dry weight compared to the untreated plants in both seasons.
3. Concerning the effect of interaction between the salinity levels and different studied foliar applications, the treatment of 25 ppm α-tocopherol gave the highest significant increases in plant height under different examined levels of water salinity compared to the untreated plants in both seasons.Generally, the treatment of 2.5 µM Na2SeO4 achieved the highest significant increases in leaf area, leaves fresh weight, stem fresh weight, total shoot fresh weight, stem dry weight and total shoot dry weight under different tested levels of salinity.
2. Leaf relative water content (LRWC)
1. All studiedfoliar applications except the treatment of 50 ppm α tocopherol in both seasons and the treatment of 25 ppm α tocopherol in the second one significantly enhanced LRWC compared to the untreated plants in both seasons.
2. Application of 2.5 µM Na2SeO4 led to the highest significant increases in LRWC under all applied levels of salinity
3. Photosynthetic pigments
1. Application of 25 ppm α tocopherol achieved the highest significant increases in Chl a, Chl b and carotenoids compared to the other treatments
2. Under the moderate level of salinity (50 mM NaC), the treatments of 2.5 and 5 µM Na2SeO4 resulted in a significant increase in Chl a/b ratio compared to those under unstressed conditions.
4. Leaf mineral Sodium and Potassium content
1. All studied foliar applications significantly reduced the concentration of Na+ in the leaf tissues of maize plants.
2. Application 25 ppm α tocopherol in the first season and 2.5 µM Na2SeO4 in the second season gave the lowest significant values in the concentration of Na+ compared to the untreated plants.
3. The highest significant increase in K+ was obtained by the treatment of 2.5 µM Na2SeO4 compared to the untreated plants in both seasons.
4. Application of 2.5 µM Na2SeO4 under the unstressed conditions resulted in the highest significant values ofK+ concentration in both seasons
5. Activity of antioxidant enzymes
1. All examined treatments positively affected the activities of POD and PPO. The treatment of 2.5 µM Na2SeO4 exhibited the highest significant results compared to the control in both seasons.
2. Application of 2.5 µM Na2SeO4 in both seasons and 5 µM Na2SeO4 or 25 ppm α tocopherol in the second season under 100 mM NaCl resulted in the highest significant values in the activity of POD compared to the other treatments.
6. Grain yield and its attributes
1. Application of 25 ppm α tocopherol achieved the highest significant increases in the ear weigh/plant, weight of grains/ear and weight of 100 grains compared to the other treatments in both seasons, whereas; plants that treated by 25 ppm or 50 ppm α tocopherol gave the highest significant increases in the ear length compared to the untreated plants in both seasons.
2. Application of 25 ppm α tocopherol under non saline conditions resulted in the highest significant increases in ear weight/plant, weight of grains/ear, weight of 100 grains and ear length compared to the other interactive treatments in both seasons.
7. Viability of the produced grains
Foliar applications indicated that the treatment of 2.5 µM Na2SeO4 or 25 ppm α- tocopherol under non saline conditions achieved the highest significant grain viability.
It was concluded from the present study that α- tocopherol and selenium could be implicated in the protection of pigments, regulating of water status and ionic balance of salt-affected plants. Furthermore, they can act as an antioxidant by increasing the activities of enzymatic antioxidant systems leading to reducing NaCl-induced oxidative damages. Thus, α- tocopherol and selenium at the optimal concentration could keep the osmotic balance and protect the different vital processes of maize plants under saline conditions. These effects could explain the improvement of growth and yield parameters under the circumstances of this study.