Document Details
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Document Type |
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Thesis |
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Document Title |
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PHYSIOLOGICAL AND BIOCHEMICAL RESPONSE OF WHEAT (TRITICUM AESTIVUM) WHEN EXPOSES TO DIFFERENT DOSES OF OZONE الاستجابة الفسيولوجية والكيموحيوية لنبات القمح (Triticum aestivum) عند تعريضه لتركيزات مختلفة من الأوزون |
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Subject |
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Faculty of Science |
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Document Language |
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Arabic |
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Abstract |
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Troposphere ozone is a dangerous air pollution that negatively affects vegetation and crops losses. Ozone causes different types of damage to crops such as leaf injury, growth reduction, reduce photosynthetic and stomatal conductance, forming ROS. All these effects cause reduction in yield quality and quantity. Many important crops are sensitive to elevated ground ozone such as wheat. ozone has harmful effects on wheat crop and thus lowering the dietary nutritional values. The aim of this study was to evaluate the effects of different levels of ozone (ambient AA (45.9 ppb), fumigation O3 (50 ppb) and filter-air FA (30ppb)) on physiological and biochemical characteristics of wheat (Triticum aestivum L.) during the life cycle, in Jeddah city. The protective effect of antiozonant ethylenediurea (EDU) on wheat response and resistance under the O3 stress was investigated. In field conditions during Jan-April 2015, plant exposed to ambient-O3 and half treated with EDU. The second study during Jan-Mar 2017, was in 2 closed fumigation chambers were plants exposed to non-filtered air plus additional O3 (50 ppb), filter-air (30 ppb) and half plant treated with (EDU) for the full growing season. The Infrared Gas Analyzer was used to measure the photosynthesis and stomatal response. Growth, yield, different pigments and antioxidant enzymes were also determined for the study of biochemical effects in response to O3 and/or EDU. The results in field experiments showed that EDU-treated plants had higher photosynthetic rates 24% and stomatal conductance (gs) (25%), which were reflected in higher growth and yield in terms of number of grains. Plants exposed to AA had higher activities of antioxidant enzymes. In the close chamber, O3 had negative effects compared to other treatment on caused significant reductions in photosynthetic rate (16.78%), stomatal conductance (23.4%), Chl b (50%), total Chl (24%), protein leave (43.4%), fiber contents by (25.2%), total carbohydrate (30.3%),while had increased activity of (SOD), (GPX), (CAT), (H2O2) and visible leaves injury (2.25-fold). Total average grain number and weight were significantly higher in EDU-treated than non-treated plants in both experiments. The study shows that harvest index increased by EDU 80%. O3 had significant decrease in grain number per ear (17.9%), dry mass of grains (48.8%) and Proline (72.7%). The present study revealed that EDU could be used as a promising tool to mitigate damaging effects of O3 on under field conditions. EDU protected wheat plants from O3 stress that leading to increases in photosynthetic rates, growth and yield. |
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Supervisor |
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Dr. Huda Abdul-Latif Qari |
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Thesis Type |
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Doctorate Thesis |
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Publishing Year |
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1440 AH
2019 AD |
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Added Date |
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Thursday, July 11, 2019 |
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Researchers
| ليلى عبد الحميد باقاسي | Baqasi, Laila Abdulhamid | Researcher | Doctorate | |
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